- phenixbb - phenix-online.org

weight optimization
by peter hudson 29 Mar '09

29 Mar '09

Hello all I am very new to this field. I am refining a dataset of 3.0A resolution. I want to perform the weight optimization. while weight optimisation, occupancy refinemnet is default. I donot want torefine the occupancy of any of the atoms from my model. How can i set to occupancy_refinemnet=false. I will appreciate the suggestions. Thanks in advance Peter

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Re: [phenixbb] Question about scale of ED maps from phenix vs map coeffs when displayed in COOT
by Ralf W. Grosse-Kunstleve 29 Mar '09

29 Mar '09

For phenix maps: the sum is over the entire unit cell. Ralf > Is the sum over the asymmetric unit or the portion of space that > happened to be covered by the map? The result of this calculation > depends greatly on the amount of solvent region that is included in > the sum. > > Dale Tronrud > > Ralf W. Grosse-Kunstleve wrote: > >> That was (and is) always a mystery for me: when I look at two maps (both > >> coming from phenix.refine): > >> - one is computed in COOT from phenix.refine map coefficients, and > >> - another one displayed in PyMol using X-plor formatted map. > >> > >> To make both maps looking identical I have to draw them at different > >> sigma levels, sometime very different. This is true for both fo-fc and > >> 2fo-fc maps. > >> > >> I have some ideas but no any proofs so I don't want to put my > >> speculations to the bb. So, I have no answer... May be Ralf or Paul E...? > > > > Our "sigmas scaled maps" are simply divided by the "biased standard > > deviation": > > > > sqrt(sum((value-mean)**2) / n) > > > > The mean of our maps is usually zero, as we don't usually include F000. > > > > Ralf

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Refinement error
by Katya Heldwein 27 Mar '09

27 Mar '09

Hi, I am getting the following error when I run phenix.refine. How can I get rid of it? Katya =============================== refinement start ============================== ----------structure factors based statistics (before refinement)---------- ----------X-ray data---------- show_stack(1): /private/var/automount/nfs/programs/i386-mac/cciapps/2009_02_15_2320/cci_apps_sources/mmtbx/twinning/twin_f_model.py(1676) r_values show_stack(2): /private/var/automount/nfs/programs/i386-mac/cciapps/2009_02_15_2320/cci_apps_sources/mmtbx/twinning/twin_f_model.py(1837) r_work show_stack(3): /private/var/automount/nfs/programs/i386-mac/cciapps/2009_02_15_2320/cci_apps_sources/mmtbx/f_model.py(2249) __init__ show_stack(4): /private/var/automount/nfs/programs/i386-mac/cciapps/2009_02_15_2320/cci_apps_sources/mmtbx/twinning/twin_f_model.py(1139) info show_stack(5): /private/var/automount/nfs/programs/i386-mac/cciapps/2009_02_15_2320/cci_apps_sources/mmtbx/__init__.py(109) show_comprehensive show_stack(6): /private/var/automount/nfs/programs/i386-mac/cciapps/2009_02_15_2320/cci_apps_sources/phenix/phenix/refinement/strategies.py(280) refinement_machine show_stack(7): /private/var/automount/nfs/programs/i386-mac/cciapps/2009_02_15_2320/cci_apps_sources/phenix/phenix/refinement/driver.py(1121) run show_stack(8): /private/var/automount/nfs/programs/i386-mac/cciapps/2009_02_15_2320/cci_apps_sources/phenix/phenix/refinement/command_line.py(89) run show_stack(9): /programs/i386-mac/cciapps/2009_02_15_2320/cci_apps_sources/phenix/phenix/command_line/refine.py(16) <module> Floating-point error (Python call stack above) This crash may be due to a problem in any imported Python module, including modules which are not part of the cctbx project. To disable the traps leading to this message, define these environment variables (e.g. assign the value 1): BOOST_ADAPTBX_FPE_DEFAULT BOOST_ADAPTBX_SIGNALS_DEFAULT This will NOT solve the problem, just mask it, but may allow you to proceed in case it is not critical. -- Ekaterina Heldwein, Ph.D. Assistant Professor Department of Molecular Biology and Microbiology Tufts University 136 Harrison Ave Boston, MA 02111 phone: 617-636-0858 fax: 617-636-0337 e-mail: katya.heldwein(a)tufts.edu

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AssertionError in twin refinement...
by Francis E Reyes 26 Mar '09

26 Mar '09

====================== bulk solvent modeling and scaling ====================== |--(resolution: 2.00 - 23.08 A; n_refl. = 24304)------------------------------| | | | r_work= 0.2462 r_free= 0.2706 ksol= 0.32 Bsol= 47.55 scale= 1.149 | | | | overall anisotropic scale matrix (Cartesian basis; B11,B22,B33,B12,B13,B23):| | (-2.11,5.80,-3.69,0.00,-0.00,-0.00); trace/3= -0.00 | | | | maximum likelihood estimate for coordinate error: None A | | x-ray target function (twin_lsq_f) for work reflections: 0.346916 | | twin fraction: 0.03 twin operator: k,h,- l | | -----------------------------------------------------------------------------| ================== ordered solvent: location/analysis/update ================== Start model: number = 165 b_iso_min = 37.62 (limit = 1.00) b_iso_max = 70.26 (limit = 50.00) b_iso_mean = 49.33 anisotropy_min = 1.00 (limit = 0.10) occupancy_min = 1.00 (limit = 1.00) occupancy_max = 1.00 (limit = 1.00) dist_sol_mol_min = 2.45 (limit = 1.80) dist_sol_mol_max = 4.94 (limit = 6.00) Filtered: number = 71 b_iso_min = 37.71 (limit = 1.00) b_iso_max = 49.89 (limit = 50.00) b_iso_mean = 45.14 anisotropy_min = 1.00 (limit = 0.10) occupancy_min = 1.00 (limit = 1.00) occupancy_max = 1.00 (limit = 1.00) dist_sol_mol_min = 2.45 (limit = 1.80) dist_sol_mol_max = 3.99 (limit = 6.00) Traceback (most recent call last): File "/usr/local/phenix-1.3-final/phenix/phenix/command_line/ refine.py", line 5, in <module> command_line.run(command_name="phenix.refine", args=sys.argv[1:]) File "/usr/local/phenix-1.3-final/phenix/phenix/refinement/ command_line.py", line 89, in run call_back_after_monitor_collect=call_back_after_monitor_collect) File "/usr/local/phenix-1.3-final/phenix/phenix/refinement/ driver.py", line 1081, in run call_back_after_monitor_collect = call_back_after_monitor_collect) File "/usr/local/phenix-1.3-final/phenix/phenix/refinement/ strategies.py", line 364, in refinement_machine log = log) File "/usr/local/phenix-1.3-final/mmtbx/mmtbx/solvent/ ordered_solvent.py", line 159, in __init__ use_kick_map = self.params.use_kick_maps).peaks_mapped() File "/usr/local/phenix-1.3-final/mmtbx/mmtbx/solvent/ ordered_solvent.py", line 332, in find_peaks log = self.log) File "/usr/local/phenix-1.3-final/mmtbx/mmtbx/find_peaks.py", line 85, in __init__ symmetry_flags = maptbx.use_space_group_symmetry) File "/usr/local/phenix-1.3-final/mmtbx/mmtbx/twinning/ twin_f_model.py", line 2244, in electron_density_map "m_gradient") AssertionError phenix version is 1.3 final. Ideas? thanks! FR --------------------------------------------- Francis Reyes M.Sc. 215 UCB University of Colorado at Boulder gpg --keyserver pgp.mit.edu --recv-keys 67BA8D5D 8AE2 F2F4 90F7 9640 28BC 686F 78FD 6669 67BA 8D5D

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Spermine molecule on a crystallographic two-fold axis
by Marjolein Thunnissen 26 Mar '09

26 Mar '09

I have been trying to find in the documentation if there is a way to do this but I have the following problem: In a recent structure we are currently refining we identified a spermine molecule sitting right on a crystallographic two-fold axis. Spermine has internal two-fold symmetry and it is part of extensive crystal contacts. I just wonder how to refine this with Phenix. In Refmac it is easy, I put the occupancies to 0.5 and the program ignores the clashes of the symmetry related molecule, but that doesn't seem to be the way that Phenix works. Can anyone give me advise on this? Thanks __________________________________________________________________________ | Marjolein Thunnissen Phone +46-(0)46-22 24584| | Associate Professor Fax +46-(0)46-22 24692| | Dept of Molecular Biophysics, Lund University http://www.mbfys.lu.se | | PO-Box 124 S-221 00 Lund, Sweden | | | |Scientific Coordinator I911 (Max-lab): MAD and fixed-wavelength stations | | for macromolecular crystallography | |__________________________________________________________________________|

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twin refine error message
by Alex Taylor 26 Mar '09

26 Mar '09

Hi, I am trying to refine using the following twin operators output from xtriage for C2221 1/2*h-1/2*k,-3/2*h-1/2*k,-l 1/2*h+1/2*k,3/2*h-1/2*k,-l but phenix.refine (vers 1.4-4 and 1.4-3) fails with the following error message: =============================== refinement start ============================== Traceback (most recent call last): File "/usr/progs/linux/phenix-1.4-4/phenix/phenix/command_line/refine.py", line 18, in <module> command_line.run(command_name="phenix.refine", args=sys.argv[1:]) File "/usr/progs/linux/phenix-1.4-4/phenix/phenix/refinement/command_line.py", line 89, in run call_back_after_monitor_collect=call_back_after_monitor_collect) File "/usr/progs/linux/phenix-1.4-4/phenix/phenix/refinement/driver.py", line 1121, in run call_back_after_monitor_collect = call_back_after_monitor_collect) File "/usr/progs/linux/phenix-1.4-4/phenix/phenix/refinement/strategies.py", line 191, in refinement_machine twin_law = sgtbx.rt_mx( params.twinning.twin_law ) RuntimeError: cctbx InternalError: /net/anaconda/scratch1/phenix/phenix-1.4-4/cctbx_project/cctbx/sgtbx/rt_mx.cpp(230): Unsuitable value for rational rotation matrix. I am running the RedHat WS 5.2 64-bit OS. Thanks for suggestions, Alex -- Alex Taylor, Ph.D. Technical Director, X-ray Crystallography Core Laboratory University of Texas Health Science Center at San Antonio Office: 210-567-3781 FAX: 210-567-6595

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Postdoc Crystallographer Position - Berkeley
by Paul Adams 24 Mar '09

24 Mar '09

Lawrence Berkeley Laboratory Postdoctoral Researcher Job ID: 22539 Division: Physical Biosciences Date Opened: 3/24/2009 Summary: A postdoctoral position is immediately available to study structure and function of macromolecular complexes and enzymes using X-ray crystallographic methods. This position is joint between the Center for Protein Folding Machinery (www.proteinfoldingcenter.org) and the Joint BioEnergy Institute (www.jbei.org). Robotic hardware for performing crystallization trials and imaging results are available. Crystals will be characterized and data collected using the beamline resources of the Berkeley Center for Structural Biology at the Advanced Light Source. The biological systems to be studied are: - Type-II chaperonins responsible for the refolding of unfolded proteins in archeal and mammalian cells. - Glycosyl transferases responsible for the synthesis of hemicellulose in plants. - Novel glycosyl hydrolases that are able to breakdown cellulosic material for biofuels production. Duties: Using robotic hardware to perform screens for crystallization conditions. Optimization of crystallization conditions. Biophysical characterization of protein samples using standard techniques, such as dynamic light scattering. Characterization of crystals using the Berkeley Center for Structural Biology beamlines at the Advanced Light Source. Collection and analysis of diffraction data, model building and structure refinement. Extensive email and verbal interaction with other researchers. Qualifications: Ph.D. or equivalent in a scientific discipline, preferably structural biology, biology, or chemistry. Demonstrated experience of scientific research using crystallographic methods. Experience with crystallization methods. Solid interpersonal skills and the ability to work in a team environment are critical. Ability to communicate with a broad range of researchers. Note that this is a one-year appointment with renewal based on performance and continued funding. Lawrence Berkeley National Laboratory is a world leader in science and engineering research, with 11 Nobel Prize recipients over the past 75 years, and 59 present members of the National Academy of Sciences. LBNL conducts unclassified research across a wide range of scientific disciplines and hosts four national user facilities. AA/EEO employer committed to the development of a safe and diverse workforce. Learn more at http://www.lbl.gov. To apply visit http://cjo.lbl.gov/ and search for the job number 22539 or visit: http://jobs.lbl.gov/LBNLCareers/details.asp?jid=22539&p=1 -- Paul Adams Deputy Division Director, Physical Biosciences Division, Lawrence Berkeley Lab Adjunct Professor, Department of Bioengineering, U.C. Berkeley Vice President for Technology, the Joint BioEnergy Institute Head, Berkeley Center for Structural Biology Building 64, Room 248 Tel: 1-510-486-4225, Fax: 1-510-486-5909 http://cci.lbl.gov/paul Lawrence Berkeley Laboratory 1 Cyclotron Road BLDG 64R0121 Berkeley, CA 94720, USA. Executive Assistant: Patty Jimenez [ PAJimenez(a)lbl.gov ] [ 1-510-486-7963 ] --

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refinement with a covalent inhibitor.
by Maia Cherney 24 Mar '09

24 Mar '09

Hi all, I am trying to refine a complex with a covalent inhibitor (E-64) that has a carboxylate group. My model has it planar, but after refinement the two oxygens of the carboxyl group get out of the plane. In the cif file generated by elbow this plane description is missing, I added it manually, but the result is the same. Maia

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ADP settings for protein and solvent
by Katya Heldwein 23 Mar '09

23 Mar '09

Hi, I'd like to refine group adps for my protein and individual adps for the solvent while refining coordinates for all atoms. How can I set that up in the command line mode? Katya -- Ekaterina Heldwein, Ph.D. Assistant Professor Department of Molecular Biology and Microbiology Tufts University School of Medicine 136 Harrison Ave Boston, MA 02111 phone: 617-636-0858 fax: 617-636-0337 e-mail: katya.heldwein(a)tufts.edu

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Question about scale of ED maps from phenix vs map coeffs when displayed in COOT
by Schubert, Carsten [PRDUS] 21 Mar '09

21 Mar '09

Hi, Sorry for the crosspost, but I am not sure were the problem is located: I noticed that the xplor maps generated by phenix seem to be on a different scale than the maps generated from the map-coefficients from the same refinement run when the maps-coeffs are read into coot. Usually I only read in the map-coeffs and the scale seems reasonable to me, i.e. average density ~0.28 e/A3 at 1 sigma for a 2fofc map. The map from the same run (converted to ccp4 map in mapman) is at 0.55e/A3 at 1 sigma, when displayed in coot. The map should be normalized in phenix (apply_sigma_scaling=True) and the stats from mapman indicate an RMS deviation of ~1. For fofc maps I need to crank up the display to 6 sigma to get an equivalently looking map as the one from the map-coefficients at 3 sigma contour level. Any hints as to were the factor of 2 comes from, coot or phenix? Cheers, Carsten

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Problems with phasing a protein (1300aa)
by Kumar 20 Mar '09

20 Mar '09

Hello Phenixbb members, I have been trying to obtain phases for a protein which contain ~1300aa. We have obtained native data to a resolution of 3.3A (Space group I222 or I212121). But we are having tough time phasing it. 'Se' labeled crystals diffracts maximally up to 3.5 to 4 A and dies very quickly on most of the beamlines. We have scanned at Se wavelength and it gives very strong signal as it contain ~45 Se in AU (1300 aa). It is difficult to collect a complete dataset (maximally we get 50-60 % completion with Rmerge ~15) out of one crystal on regular beamline. At microfocus beamline (APS), we were able to collect data in 3-4 batches and merge them to get a complete dataset (Rmerge ~18-20) out of one crystal. We used data collected on microfocus beamline (at peak wavelength) for locating heavy atom position using SHELXD, Solve and Phenix.hyss. SOlve and Phenix.hyss find very few heavy atom sites 1-5 whereas SHELX-CDE lists many but shows no difference in original and inverted (contrast and connectivity). Our phasing attempts with datasets obtained after merging two incomplete dataset from two different crystal has also been disappointing. My another worry is absolute value of average intensity, which seems to be quite low in most of the datasets. Below I have pasted last table of scale.log (HKL2000). Shell Lower Upper Average Average Norm. Linear Square limit Angstrom I error stat. Chi**2 R-fac R-fac 50.00 7.53 45.4 1.6 1.3 1.295 0.055 0.047 7.53 5.98 11.4 1.3 1.3 0.672 0.135 0.114 5.98 5.23 11.2 1.6 1.6 0.643 0.171 0.152 5.23 4.75 16.8 2.0 1.9 0.736 0.148 0.118 4.75 4.41 18.8 2.2 2.2 0.739 0.143 0.132 4.41 4.15 14.6 2.4 2.4 0.653 0.190 0.175 4.15 3.94 11.3 2.5 2.5 0.582 0.247 0.226 3.94 3.77 10.1 2.8 2.8 0.511 0.280 0.191 3.77 3.63 8.0 3.1 3.1 0.450 0.315 0.285 3.63 3.50 7.6 3.3 3.2 0.483 0.311 0.270 All reflections 15.5 2.3 2.2 0.694 0.153 0.106 Now, I want you to help me by answering some of my queries: 1. Is it possible to get MAD/SAD phasing done from a dataset having more than 15% Rmerge and resolution in the range of 4 - 4.5 Ang? 2. Will a complete data set obtained from merging various batches(30-40 frames each) from one or more than one crystal will have proper anomalous signal for phasing? I am worried as weak anomalous signal may get lost while merging. 3. Will such a low value of average Intensities (as shown above from HKL scale log file) will be good enough for MAD/SAD phasing or I really need to improve crystal quality for stronger diffraction. 4. For MAD/SAD phasing, till what resolution we need to have anomalous signal ? Many of my datasets shows anomalous signal maximally up to 6-8 A (calculated using Phenix.xtriage). 5. Since I have low resolution (3.5 to 4 A)data, relatively high Rmerge (14-15%), lower value of average intensity, anomalous signal up to 6 A or so..... which programs will be more useful for heavy atom location and to prevent false positives from being selected? We have been also trying our luck with heavy atom soak but that also has not been very encouraging. I would appreciate any suggestions in this regard. Thanks in advance and sorry for such a long mail. Kumar

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question about generating cif and pdb file using elbow
by crystallogrphy 20 Mar '09

20 Mar '09

Hi, I am using phenix.elbow to generate pdb and cif files with the tripos format file: phenix.elbow --initial_geometry egcg.mol2 --opt --output="LIG" --pdb-ligand The input pdb file contains hydrogen atoms and the output pdb file also contains hydrogen atom. My crystal data only difftracted to 2.4A, so hydrogen atoms cannot be seen. In the refinement, my ligand should not contain hydrogen atoms. So I add one more option not to add hydrogen following the online phenix documentation: phenix.elbow --initial_geometry --write-hydrogens=False egcg.mol2 --opt --output="LIG" --pdb-ligand *However, the program failed. Does anyone know why?* Usage: phenix.elbow [options] *phenix.elbow: error: no such option: --write-hydrogens* -- Qun Wan Department of Pharmacology, Case Western Reserve University 10900 Euclid Avenue, Cleveland, OH 44106 email: qunwan1(a)gmail.com lab phone: 216-368-3337

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Problems with kicked maps in 1.4.3 or 1.4.4
by Schubert, Carsten [PRDUS] 20 Mar '09

20 Mar '09

Hi Pavel, I am having some problems with kicked maps. The job fails with a cryptic message: "Sorry Duplicate mtz_label_amplitudes: 2FOFCWT" and nothing gets written I noticed this in 1.4.3 a couple of days ago, just upgraded to 1.4.4, same problem. Running the same job w/o kicked maps enabled runs fine. Any ideas? Cheers, Carsten Here is a snipped of the .def file. output { prefix = "Prim_105_D6" serial = 4 serial_format = "%03d" write_eff_file = True write_geo_file = False write_def_file = True export_final_f_model = mtz cns write_maps = True write_map_coefficients = True } electron_density_maps { map_format = *xplor map_coefficients_format = *mtz phs suppress = None map { mtz_label_amplitudes = None mtz_label_phases = None likelihood_weighted = None obs_factor = None calc_factor = None kicked = False fill_missing_f_obs_with_weighted_f_model = True } map { mtz_label_amplitudes = "2FOFCWT_no_fill" mtz_label_phases = "PH2FOFCWT_no_fill" likelihood_weighted = True obs_factor = 2 calc_factor = 1 kicked = False fill_missing_f_obs_with_weighted_f_model = False } map { mtz_label_amplitudes = "FOFCWT_no_fill" mtz_label_phases = "PHFOFCWT_no_fill" likelihood_weighted = True obs_factor = 1 calc_factor = 1 kicked = False fill_missing_f_obs_with_weighted_f_model = False } map { mtz_label_amplitudes = "2FOFCWT" mtz_label_phases = "PH2FOFCWT" likelihood_weighted = True obs_factor = 2 calc_factor = 1 kicked = True fill_missing_f_obs_with_weighted_f_model = True } map { mtz_label_amplitudes = "FOFCWT" mtz_label_phases = "PHFOFCWT" likelihood_weighted = True obs_factor = 1 calc_factor = 1 kicked = True fill_missing_f_obs_with_weighted_f_model = True } anomalous_difference_map { mtz_label_amplitudes = "ANOM" mtz_label_phases = "PHANOM" } grid_resolution_factor = 0.25 region = *selection cell atom_selection = None atom_selection_buffer = 3 apply_sigma_scaling = True apply_volume_scaling = False }

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Re: [phenixbb] Can Phenix do MR with medium/low res EM models?
by Gino Cingolani 19 Mar '09

19 Mar '09

thanks Ed, I'll look it up.... I kind of tried something similar but never worked in my hands. I'll give it another try! By the way, the address of my house is 107 Ardsley Drive Dewitt 13214, NY. See you on Saturday 10 or so. Give me a call if you have problems 315 657 4805 Gino *********************************************************** Gino Cingolani, Ph.D. Assistant Professor Dept. of Biochemistry and Molecular Biology SUNY Upstate Medical University 750 E. Adams Street, Syracuse, NY, 13210 Tel. (315) 464 8744 Fax. (315) 464 8750 Email: cingolag(a)upstate.edu *********************************************************** "Nati non foste per viver come bruti, ma per seguir virtute e conoscenza" ("You were not born to live like brutes, but to follow virtue and knowledge") Dante, The Divine Comedy (Inferno, XXVI, vv. 119-120)

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IndexError
by Huiying Li 19 Mar '09

19 Mar '09

I was running phenix refinement using the following command: phenix.refine data.mtz model.pdb \ strategy=individual_sites+tls+individual_adp \ my_lib.cif tls.params the run crashed with the error: ...... ...... File "/usr/local/phenix-1.3-final/mmtbx/mmtbx/monomer_library/pdb_interpretation.py", line 970, in get_lib_link atom_dicts[angle.atom_3_comp_id].get(angle.atom_id_3, None)] IndexError: list index out of range Is the index error refering to some problem in the reflection file (mtz)? Thanks for any suggestions. Huiying _____ Huiying Li, Ph. D Department of Molecular Biology and Biochemistry Natural Sciences I, Rm 2443 University of California at Irvine Irvine, CA 92697, USA Tel: 949-824-4322(or -1953); Fax: 949-824-3280 email: hli(a)uci.edu

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Can Phenix do MR with medium/low res EM models?
by Gino Cingolani 19 Mar '09

19 Mar '09

Hi Phenix community, I was wondering if Phenix can handle MR starting from medium/low res EM models. I have a very large oligomeric protein (2.4MDa) with lots of NCS and >450 Se-Mets. In principle, I could use low res MR phases from the "replaced" model to locate Se-sites and then NCS-averaging to locate more sites and improve my phases. Any suggestions how to get Phenix to use an EM model? Has anybody done it successfully using Phenix? Thanks in advance, Gino *********************************************************** Gino Cingolani, Ph.D. Assistant Professor Dept. of Biochemistry and Molecular Biology SUNY Upstate Medical University 750 E. Adams Street, Syracuse, NY, 13210 Tel. (315) 464 8744 Fax. (315) 464 8750 Email: cingolag(a)upstate.edu *********************************************************** "Nati non foste per viver come bruti, ma per seguir virtute e conoscenza" ("You were not born to live like brutes, but to follow virtue and knowledge") Dante, The Divine Comedy (Inferno, XXVI, vv. 119-120)

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Re: [phenixbb] Can Phenix do MR with medium/low res EM models?
by Thomas C. Terwilliger 19 Mar '09

19 Mar '09

Hi Gino, I have never tried any problem of this size...but here is a way to proceed using Randy's "input_partpdb_file" option for Phaser that is now available in the autosol wizard. Take your EM model with all its NCS copies, and give it to AutoSol with the keywords: input_partpdb_file=MR.pdb partpdb_rms= 3.0 The partpdb_rms should be the estimated RMSD between the MR model and the true model. You will have as good an idea about this as anyone... You also would supply the usual information to autosol: phenix.autosol sad-data.sca seq.dat 450 Se f_prime=-8 f_double_prime=4.5 \ build=False input_partpdb_file=MR.pdb\ partpdb_rms=3.0 \ resolution=6.0 You might cut the resolution to a pretty low value like 6 A as above. If you get a lot of good sites refined by phaser, then you may be on the right track. This autosol run will output phaser_1.mtz and also resolve_1.mtz that you can use as a starting point for further density modification and model-building as appropriate. Given the size of this problem, I would anticipate lots of challenges, and we will be happy to help as you carry on with it. You might try running everything at really low resolution (20A) at first just to get things to run... All the best, Tom T Hi Phenix community, I was wondering if Phenix can handle MR starting from medium/low res EM models. I have a very large oligomeric protein (2.4MDa) with lots of NCS and >450 Se-Mets. In principle, I could use low res MR phases from the "replaced" model to locate Se-sites and then NCS-averaging to locate more sites and improve my phases. Any suggestions how to get Phenix to use an EM model? Has anybody done it successfully using Phenix? Thanks in advance, Gino *********************************************************** Gino Cingolani, Ph.D. Assistant Professor Dept. of Biochemistry and Molecular Biology SUNY Upstate Medical University 750 E. Adams Street, Syracuse, NY, 13210 Tel. (315) 464 8744 Fax. (315) 464 8750 Email: cingolag(a)upstate.edu *********************************************************** "Nati non foste per viver come bruti, ma per seguir virtute e conoscenza" ("You were not born to live like brutes, but to follow virtue and knowledge") Dante, The Divine Comedy (Inferno, XXVI, vv. 119-120) _______________________________________________ phenixbb mailing list phenixbb(a)phenix-online.org http://www.phenix-online.org/mailman/listinfo/phenixbb

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omit maps without density modification?
by NATHAN THOMSEN 17 Mar '09

17 Mar '09

Hi, Is there is a way to calculate simple omit maps and sa-omit maps in phenix without using density modification? The density modification seems to be flattening the weaker regions of my map - when compared to omit maps from cns for instance. Thanks! Nathan

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AutoBuild error: csh word too long
by Zheng Zhou 16 Mar '09

16 Mar '09

Hi, All I am new to phenix. I met the following error when I run autobuild. I also found the following link from Dr. Lang asking the similar question. But I didn't find a clear solution. Thanks for your help. http://www.phenix-online.org/pipermail/phenixbb/2008-June/001087.html Starting job 1... ******************************************************************************** Failed to carry out AutoBuild_build_cycle: child process stderr output: command: 'csh /home/zz/AutoBuild_run_1_/TEMP0/RUN_FILE_1' Word too long. ******************************************************************************** Zheng

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Covalent ligands
by cdas＠purdue.edu 14 Mar '09

14 Mar '09

Greetings everyone: I have been dealing with a structure of a protein that has a Cys residue covalently modified with a peptide fluromethyl ketone. Can someone tell me how to include this ligand in phenix.refine? In the past, I have used CNS for this purpose. I created a topology and parameter file (using ProDrug server) and modified a patch in the refine script in CNS to establish a covalent connection between an atom in the ligand and gamma sulfur of the protein in question. Thanks. Chitta

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Beamtime proposal deadline for ALS GU time
by Peter Zwart 12 Mar '09

12 Mar '09

The deadline for the may/June cycle of general user time for PX in the ALS is coming up soon (This Sunday). The Berkeley Center for Structural Biology (BCSB) has recently completed a number of upgrades: Sector 8: Recent improvements include: * A high-accuracy microdiffractometer on BL 8.2.1 allows for centering and viewing of very small crystals; * Robot automounters on BL8.2.1 and 8.2.2 are now fully commissioned and the beamlines can be used remotely; * A new large format (315mm active surface area) CCD detector on BL 8.2.1 facilitates data collection on large unit cell crystals. Sector 5: Recent improvements include: * Beamlines (5.0.1 and 5.0.3) now generate 1.5x1011 photons per second at 0.97 Angstrom. This wavelength is slightly above the Se K edge making them ideal for performing Se SAD experiments. * Beamline 5.0.2 (the tunable beamline) generates a peak flux of 8x1011 photons per second, and the energy range of 5.0.2 has been extended to 17 keV, enabling the routine use of shorter wavelengths and anomalously scattering elements such as bromine. * All sector 5 beamlines can be run remotely. The automated sample mounter holds six pucks (96 sample in total). On weekdays, staff is available 22 hours (out of 24) for puck changes and assistance. Please visit http://bcsb.lbl.gov/ for more details about the Center and its beamlines. If you'd like to apply for May/June beamtime at the Advanced Light Source, please submit a General User proposal by March 15, 2009. To find out more, click on: http://www-als.lbl.gov/als/quickguide/independinvest.html We invite you to submit a proposal at: http://alsusweb.lbl.gov/4DCGI/WEB_GetForm/PXProposalEntry.shtml/Initialize. If you have any questions or would like to request open beamtime, please e-mail BCSBBeamtime(a)lbl.gov. [Please note that executed user agreements must be received by LBNL prior to beamtime. Proprietary fees, if applicable, must be received by LBNL at least five working days prior to scheduled beamtime.] -- ----------------------------------------------------------------- P.H. Zwart Beamline Scientist Berkeley Center for Structural Biology Lawrence Berkeley National Laboratories 1 Cyclotron Road, Berkeley, CA-94703, USA Cell: 510 289 9246 BCSB: http://bcsb.als.lbl.gov PHENIX: http://www.phenix-online.org CCTBX: http://cctbx.sf.net -----------------------------------------------------------------

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Re: [phenixbb] phenix.multi_crystal_average with twinned data
by Thomas C. Terwilliger 11 Mar '09

11 Mar '09

Hi Peter and Mary, For the cross-crystal averaging procedure, no refinement is done, so no problem about using detwinned data in phenix.refine. in this case. If detwinned data is supplied then it will be used for density modification. That is probably the best procedure at present. (Note that when running autobuild, you can input a specific "input_refinement_file" for refinement (raw data) and separately specify an input_map_file with a map and a data file with (optionally) detwinned data.) All the best, Tom T Hi, Detwinning is possible with xtriage or phenix.refine (on way or the other). Integrating this into density modification might be hard, especially when the twin fraction is high. What is your twin fraction? Tom, Is it possible to use a different set of amplitudes for density modification then for refinement? You wouldn't want to refine against detwinned data. Cheers Peter 2009/3/11 Thomas C. Terwilliger <terwilliger(a)lanl.gov>: > Hi Mary, > > I have not tried the phenix multi-crystal averaging procedure with > twinned > data, but here are some suggestions of how to proceed. > > 1. This routine does not do any refinement, only density modification. > The density modification step does not know about twinning, so it will > be > necessary (if your data are significantly twinned) to supply structure > factor files with detwinned data. I will check with Peter Zwart on > producing detwinned data in phenix; it may be necessary to do that with > other tools as normally phenix.refine uses the original data and does > the > calculations internally. > > 2. The models you supply are used to (a) identify NCS symmetry and > cross-crystal symmetry. Therefore it should not really matter if these > models are incomplete, and therefore the approach you are using should > work for improving the region where you have no model. The region where > NCS is applied is defined as a region centered near the center-of-mass > of > the supplied model over which the NCS correlation is high. > > > I hope that helps! > All the best, > Tom T > > > I started running this function and then realized that I probably need > to > do something to take the perfect twinning into account. I'm not sure of > the best way to do this. I believe the map coefficients output by a run > phenix.refine should be detwinned as I give a twin law when running > phenix.refine. Should I detwin the mtz containing the data and then use > those files for the multi crystal averaging? Is there a way to output > detwinned data mtz files in phenix or do I need to use another program? > > Also, I have two ncs copies in the ASU. There's a region of density in > both ncs copies that I'm trying to improve the maps for with the multi > crystal averaging. I don't have anything built in the region yet. Is > there a way to use the NCS and multi crystal averaging at the same time > without any pdb coordinates in that region? > > Even with my goof up about the twinning, the eff script I created > appeared to run without problems. > > Thanks, > > Mary X. Fitzgerald > Postdoctoral Associate > Arnold Lab > _______________________________________________ > phenixbb mailing list > phenixbb(a)phenix-online.org > http://www.phenix-online.org/mailman/listinfo/phenixbb > > > > > _______________________________________________ > phenixbb mailing list > phenixbb(a)phenix-online.org > http://www.phenix-online.org/mailman/listinfo/phenixbb > -- ----------------------------------------------------------------- P.H. Zwart Beamline Scientist Berkeley Center for Structural Biology Lawrence Berkeley National Laboratories 1 Cyclotron Road, Berkeley, CA-94703, USA Cell: 510 289 9246 BCSB: http://bcsb.als.lbl.gov PHENIX: http://www.phenix-online.org CCTBX: http://cctbx.sf.net -----------------------------------------------------------------

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Re: [phenixbb] phenix.multi_crystal_average with twinned data
by Thomas C. Terwilliger 11 Mar '09

11 Mar '09

Hi Mary, I have not tried the phenix multi-crystal averaging procedure with twinned data, but here are some suggestions of how to proceed. 1. This routine does not do any refinement, only density modification. The density modification step does not know about twinning, so it will be necessary (if your data are significantly twinned) to supply structure factor files with detwinned data. I will check with Peter Zwart on producing detwinned data in phenix; it may be necessary to do that with other tools as normally phenix.refine uses the original data and does the calculations internally. 2. The models you supply are used to (a) identify NCS symmetry and cross-crystal symmetry. Therefore it should not really matter if these models are incomplete, and therefore the approach you are using should work for improving the region where you have no model. The region where NCS is applied is defined as a region centered near the center-of-mass of the supplied model over which the NCS correlation is high. I hope that helps! All the best, Tom T I started running this function and then realized that I probably need to do something to take the perfect twinning into account. I'm not sure of the best way to do this. I believe the map coefficients output by a run phenix.refine should be detwinned as I give a twin law when running phenix.refine. Should I detwin the mtz containing the data and then use those files for the multi crystal averaging? Is there a way to output detwinned data mtz files in phenix or do I need to use another program? Also, I have two ncs copies in the ASU. There's a region of density in both ncs copies that I'm trying to improve the maps for with the multi crystal averaging. I don't have anything built in the region yet. Is there a way to use the NCS and multi crystal averaging at the same time without any pdb coordinates in that region? Even with my goof up about the twinning, the eff script I created appeared to run without problems. Thanks, Mary X. Fitzgerald Postdoctoral Associate Arnold Lab _______________________________________________ phenixbb mailing list phenixbb(a)phenix-online.org http://www.phenix-online.org/mailman/listinfo/phenixbb

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phenix.multi_crystal_average with twinned data
by Mary Fitzgerald 11 Mar '09

11 Mar '09

I started running this function and then realized that I probably need to do something to take the perfect twinning into account. I'm not sure of the best way to do this. I believe the map coefficients output by a run phenix.refine should be detwinned as I give a twin law when running phenix.refine. Should I detwin the mtz containing the data and then use those files for the multi crystal averaging? Is there a way to output detwinned data mtz files in phenix or do I need to use another program? Also, I have two ncs copies in the ASU. There's a region of density in both ncs copies that I'm trying to improve the maps for with the multi crystal averaging. I don't have anything built in the region yet. Is there a way to use the NCS and multi crystal averaging at the same time without any pdb coordinates in that region? Even with my goof up about the twinning, the eff script I created appeared to run without problems. Thanks, Mary X. Fitzgerald Postdoctoral Associate Arnold Lab

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March 15, 2009 deadline- User proposal submission for Collaborative Crystallography at BCSB
by Banumathi Sankaran 10 Mar '09

10 Mar '09

Dear Users, Deadline for May/June 2009 proposals will be March 15, 2009. Through the Collaborative Crystallography Pilot Program (CC) at the Advanced Light Source, scientists can send protein crystals to Berkeley Center for Structural Biology (BCSB) staff researchers for data collection and analysis. The CC Pilot Program can provide a number of benefits to researchers: * Obtain high quality data and analysis through collaborating with expert beamline researchers; * Rapid turn around on projects; and * Reduced travel costs. Thumbnail Description: ====================== The Collaborative Crystallography program will be piloted on beamlines 5.0.1 and 5.0.2 for one year; if successful it will be implemented on a permanent basis. CC proposals will go through the regular ALS General User proposal review process for beamtime allocation. Proposals are reviewed and ranked by the Proposal Study Panel, and beamtime is allocated accordingly. BCSB staff schedule the CC projects to fit into the available resources. Only non-proprietary projects will be accepted. As a condition of participation, BCSB staff researchers who participate in data collection and/or analysis must be appropriately acknowledged - typically being included as authors on publications and in PDB depositions. Please consult the website for additional information at: http://bcsb.als.lbl.gov/wiki/index.php/Collaborative_Crystallography ============= How To Apply: To submit a proposal, go to: http://www-als.lbl.gov/als/quickguide/independinvest.html Click on "protein crystallography" to begin proposal. For question 3 select "Collaborative PX 501/502." For question 9, please describe a specific research project with a clear end point. In order to request CC time for May/June 2009 allocation period, proposals must be submitted by March 15, 2009. The deadline for CC proposals for the time period July/August 2009 will be May 15, 2009. Regards, Banumathi Sankaran

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ADP group definitions
by Roeland Boer 09 Mar '09

09 Mar '09

Dear all, I have a question regarding the definition of the ADP groups. I'm refining a structure using a different isotropic B for each domain, while applying TLS for some mobile domains (I'm also using NCS restraints for all equivalent domains). In the refinement log file, however, the isotropic B of the domains refined with TLS, as reported in the "TLS refinement" section, is equal to the B of the starting model in all refinement macro cycles. It seems, therefore, that the isoB for the TLS groups in not refined, although I've included these domains in the .adp.group definitions (the log file actually confirms that there are 7 adp groups). Is it possible to refine TLS and isotropic B's on the same part of a model? I include the input file below. Thanks for any suggestions, Roeland Boer. refinement.input.xray_data.labels=F refinement.refine.strategy=tls+individual_sites+group_adp refinement.refine.adp.tls="chain A and resid 4:132" refinement.refine.adp.tls="chain B and resid 4:132" refinement.refine.adp.tls="chain C and resid 4:132" refinement.refine.adp.tls="chain X and resid 4:132" refinement.refine.adp.tls="chain Y and resid 4:132" refinement.refine.adp.tls="chain Z and resid 4:132" refinement.refine.adp.one_adp_group_per_residue=False refinement.refine.adp.group="resid 133:203" refinement.refine.adp.group="chain A and resid 4:132" refinement.refine.adp.group="chain B and resid 4:132" refinement.refine.adp.group="chain C and resid 4:132" refinement.refine.adp.group="chain X and resid 4:132" refinement.refine.adp.group="chain Y and resid 4:132" refinement.refine.adp.group="chain Z and resid 4:132" refinement.main.number_of_macro_cycles=4 refinement.input.xray_data.low_resolution=20.0 refinement.input.xray_data.high_resolution=3.4 refinement.main.ncs = True refinement.ncs.find_automatically = False refinement.ncs.restraint_group { reference = chain A and resid 133:203 selection = chain B and resid 133:203 selection = chain C and resid 133:203 selection = chain X and resid 133:203 selection = chain Y and resid 133:203 selection = chain Z and resid 133:203 } refinement.ncs.restraint_group { reference = chain B and resid 4:132 selection = chain A and resid 4:132 selection = chain C and resid 4:132 selection = chain X and resid 4:132 selection = chain Y and resid 4:132 selection = chain Z and resid 4:132 } refinement.output.prefix=test

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RuntimeError: Not enough memory for cubicles:
by Gino Cingolani 09 Mar '09

09 Mar '09

Dear Phenix community, I am still having problems to refine a large unit cell (~13,500 residues/asymmetric unit). The refinement goes well but at the very last cycle, immediately prior to outputting the refined model, phenix stops with the following error message: $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ ========== residual map mFobs-DFmodel: highest peaks and deepst holes ========= ----------peaks---------- Traceback (most recent call last): File "/usr/local/phenix-1.4-3/phenix/phenix/command_line/refine.py", line 9, in <module> command_line.run(command_name="phenix.refine", args=sys.argv[1:]) File "/usr/local/phenix-1.4-3/phenix/phenix/refinement/command_line.py", line 89, in run call_back_after_monitor_collect=call_back_after_monitor_collect) File "/usr/local/phenix-1.4-3/phenix/phenix/refinement/driver.py", line 1098, in run call_back_after_monitor_collect = call_back_after_monitor_collect) File "/usr/local/phenix-1.4-3/phenix/phenix/refinement/strategies.py", line 710, in refinement_machine fmodels=fmodels, model=model, log=log) File "/usr/local/phenix-1.4-3/phenix/phenix/refinement/strategies.py", line 738, in highest_peaks_and_deepest_holes_in_residual_map log = log) File "/usr/local/phenix-1.4-3/mmtbx/find_peaks.py", line 212, in show_highest_peaks_and_deepest_holes log = log) File "/usr/local/phenix-1.4-3/mmtbx/find_peaks.py", line 117, in __init__ map = fft_map_data).all(max_clusters = max_number_of_peaks) File "/usr/local/phenix-1.4-3/cctbx/maptbx/__init__.py", line 196, in peak_search max_clusters=parameters.max_clusters()) File "/usr/local/phenix-1.4-3/cctbx/maptbx/__init__.py", line 303, in __init__ general_positions_only=self._general_positions_only) File "/usr/local/phenix-1.4-3/cctbx/crystal/__init__.py", line 479, in site_cluster_analysis cubicle_epsilon=cubicle_epsilon) RuntimeError: Not enough memory for cubicles: This may be due to unreasonable parameters: cubicle_edge=0.7 space_span=(293.298,92.903,214.527) n_cubicles=(419,133,307) max_number_of_bytes=1724676096 Traceback (most recent call last): File "/usr/local/phenix-1.4-3/phenix/phenix/command_line/refine.py", line 9, in <module> command_line.run(command_name="phenix.refine", args=sys.argv[1:]) File "/usr/local/phenix-1.4-3/phenix/phenix/refinement/command_line.py", line 89, in run call_back_after_monitor_collect=call_back_after_monitor_collect) File "/usr/local/phenix-1.4-3/phenix/phenix/refinement/driver.py", line 1098, in run call_back_after_monitor_collect = call_back_after_monitor_collect) File "/usr/local/phenix-1.4-3/phenix/phenix/refinement/strategies.py", line 710, in refinement_machine fmodels=fmodels, model=model, log=log) File "/usr/local/phenix-1.4-3/phenix/phenix/refinement/strategies.py", line 738, in highest_peaks_and_deepest_holes_in_residual_map log = log) File "/usr/local/phenix-1.4-3/mmtbx/find_peaks.py", line 212, in show_highest_peaks_and_deepest_holes log = log) File "/usr/local/phenix-1.4-3/mmtbx/find_peaks.py", line 117, in __init__ map = fft_map_data).all(max_clusters = max_number_of_peaks) File "/usr/local/phenix-1.4-3/cctbx/maptbx/__init__.py", line 196, in peak_search max_clusters=parameters.max_clusters()) File "/usr/local/phenix-1.4-3/cctbx/maptbx/__init__.py", line 303, in __init__ general_positions_only=self._general_positions_only) File "/usr/local/phenix-1.4-3/cctbx/crystal/__init__.py", line 479, in site_cluster_analysis cubicle_epsilon=cubicle_epsilon) RuntimeError: Not enough memory for cubicles: This may be due to unreasonable parameters: cubicle_edge=0.7 space_span=(293.298,92.903,214.527) n_cubicles=(419,133,307) max_number_of_bytes=1724676096 $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ Following the various suggestions received after my previous email (~2 weeks ago), I have tried the following: --> Using phenix 1.4-3, which gave exactly the same problem as phenix 1.3 --> Using MACRO_CYCLE=0 before refinement to see if phenix can write out such a large asymmetric unit, and that works. Phenix does write out the model at a starting Rfree ~35.5%. --> Removing ordered_solvent=true Right now the refinement scheme I am using is as follows: phenix.refine XX.mtz model.pdb simulated_annealing=true elbow.XX_pdb.cif strategy=individual_sites+group_adp+tls tls_group_selections.params main.number_of_macro_cycles=5 main.ncs=true refinement.ncs.excessive_distance_limit=None refinement.pdb_interpretation.clash_guard.nonbonded_distance_threshold=No Once again, the refinement proceeds smoothly for 2-3 days; the Rfree drops nearly 3 points, and right at the very end, the programs stops without outputting a refined model. Does anybody have any idea what's going on? Thanks, Gino *********************************************************** Gino Cingolani, Ph.D. Assistant Professor Dept. of Biochemistry and Molecular Biology SUNY Upstate Medical University 750 E. Adams Street, Syracuse, NY, 13210 Tel. (315) 464 8744 Fax. (315) 464 8750 Email: cingolag(a)upstate.edu *********************************************************** "Nati non foste per viver come bruti, ma per seguir virtute e conoscenza" ("You were not born to live like brutes, but to follow virtue and knowledge") Dante, The Divine Comedy (Inferno, XXVI, vv. 119-120)

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installation : cctbx or cci apps
by Bryan W. Lepore 09 Mar '09

09 Mar '09

i hope this is a "yes" or "no" question : i just got the latest phenix and the latest cci_apps running together. is the latest cctbx necessary? -bryan

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Restraints on water molecules
by Engin Ozkan 09 Mar '09

09 Mar '09

Are restraints on water molecules overwritten on successive cycles of refinement where ordered solvent is on? I seem to lose my distance restraints between specific waters and metal, unless I name my water molecules something else (and supply phenix with a cif for that name which is identical to water inside). The distance restraints also seem to be in effect for all cycles if ordered_solvent is off. I am also trying to make sure water numbers don't change during solvent picking/deleting. Engin

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PDF slides: introduction to refinement, phenix.refine and why automation is important (PHENIX)
by Pavel Afonine 09 Mar '09

09 Mar '09

Dear PHENIX community: I would like to draw your attention to these two PDF files with the slides that I recently made for a PHENIX workshop (workshop on Neutron crystallography, March 5-6, Japan). The first file (69 of very dense slides) makes a general introduction to crystallographic structure refinement (certainly biased towards how things are done in phenix.refine), plus some introduction to phenix.refine functionality. The second PDF file talks about PHENIX and "quick validation" with the strong accent of why automation is important. In general, I don't like and normally don't do such advertisements, but in this case I believe I can make an exception since I spent too much "of my software development" time on making these slides and they might be instructive for (new) PHENIX users. The links are (the first two!): http://www.phenix-online.org/presentations/neutron_japan_2009/ Thanks, Pavel. PS> Two slides in the first file are borrowed from Sasha Urzhumtsev, and 2-3 slides are borrowed from Paul Adams (second file).

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Re: [phenixbb] phenixbb Digest, Vol 40, Issue 7
by Pascal Egea 08 Mar '09

08 Mar '09

Pavel and Paul, this is really awesome.Thanks a lot. Pascal Egea UCSF Department of Biochemistry and Biophysics Laboratory of Robert Stroud On Sun, Mar 8, 2009 at 1:00 PM, <phenixbb-request(a)phenix-online.org> wrote: > Send phenixbb mailing list submissions to > phenixbb(a)phenix-online.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.phenix-online.org/mailman/listinfo/phenixbb > or, via email, send a message with subject or body 'help' to > phenixbb-request(a)phenix-online.org > > You can reach the person managing the list at > phenixbb-owner(a)phenix-online.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of phenixbb digest..." > > > Today's Topics: > > 1. PDF slides: introduction to refinement, phenix.refine and why > automation is important (PHENIX) (Pavel Afonine) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sat, 07 Mar 2009 23:41:35 -0800 > From: Pavel Afonine <PAfonine(a)lbl.gov> > Subject: [phenixbb] PDF slides: introduction to refinement, > phenix.refine and why automation is important (PHENIX) > To: phenixbb(a)phenix-online.org > Message-ID: <49B376AF.1020803(a)lbl.gov> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Dear PHENIX community: > > I would like to draw your attention to these two PDF files with the > slides that I recently made for a PHENIX workshop (workshop on Neutron > crystallography, March 5-6, Japan). > > The first file (69 of very dense slides) makes a general introduction to > crystallographic structure refinement (certainly biased towards how > things are done in phenix.refine), plus some introduction to > phenix.refine functionality. > > The second PDF file talks about PHENIX and "quick validation" with the > strong accent of why automation is important. > > In general, I don't like and normally don't do such advertisements, but > in this case I believe I can make an exception since I spent too much > "of my software development" time on making these slides and they might > be instructive for (new) PHENIX users. > > The links are (the first two!): > > http://www.phenix-online.org/presentations/neutron_japan_2009/ > > Thanks, > Pavel. > > PS> Two slides in the first file are borrowed from Sasha Urzhumtsev, and > 2-3 slides are borrowed from Paul Adams (second file). > > > > > ------------------------------ > > _______________________________________________ > phenixbb mailing list > phenixbb(a)phenix-online.org > http://www.phenix-online.org/mailman/listinfo/phenixbb > > > End of phenixbb Digest, Vol 40, Issue 7 > *************************************** >

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Re: [phenixbb] refinement using a multiprocessor machine or on a cluster
by Pavel Afonine 07 Mar '09

07 Mar '09

Hi Gino, phenix.refine does not use any advantage of multiple available CPUs. Sorry. Pavel. On 3/4/09 11:26 AM, Gino Cingolani wrote: > Dear Phenix community, > > I was wondering if it is possible to run a refinement job on multiple > processor. The refinement of my 13,000 asymmetric unit takes about 2 > days. It could be greatly speeded up by taking advantage of the 4 CPUs > in my PC. The phenix manual suggest to use > nproc=3 > to run using a multiprocessor machine or on a cluster. > But this applies only to LigandFit and AutoBuild Wizards. > What about simple refinement? > > Thanks in advance, > > Gino > >

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fwd: TLS without isotropic adp refinement
by Nathaniel Echols 07 Mar '09

07 Mar '09

(I think the server must have a lag time between adding a new email address and accepting posts from it. . .) > From: Roeland Boer <rbocri(a)ibmb.csic.es> > Date: March 5, 2009 5:29:19 AM PST > To: phenixbb(a)phenix-online.org > Subject: TLS without isotropic adp refinement > > Dear all, > > I'm trying to refine a structure using TLS on some of the domains > without refining the isotropic B factors of the atoms of the full > structure. I haven't been able to do this: the isotropic B factors > seem to be refined per residue when I include TLS. If I don't use > TLS, the B factors are not refined. I've looked around in the > archives and browsed the manual without luck. Any suggestions would > be highly appreciated. I include the parameter file I've used. Quoting Pavel (since he's teaching a workshop): "phenix.refine always writes out the total B-factors and not split them. The total B-factor in phenix.refine is defined as: Utotal = Utls + Ulocal + Ucryst." So the atomic B-factors in your structure are not being refined individually, but they change anyway because the contribution of the TLS refinement is included. -Nat > > Kind regards, > Roeland Boer. > > > ++++++++++++++ Parameters ++++++++++++++++ > > refinement.main.number_of_macro_cycles=4 > refinement.main.ncs = True > refinement.input.xray_data { > labels=F > low_resolution=20.0 > high_resolution=3.6 > } > refinement.refine { > strategy=tls+individual_sites > adp { > tls="chain A and (resid 4:132 or resid 301)" > tls="chain B and (resid 4:132 or resid 301)" > tls="chain C and (resid 4:132 or resid 301)" > tls="chain X and (resid 4:132 or resid 301)" > tls="chain Y and (resid 4:132 or resid 301)" > tls="chain Z and (resid 4:132 or resid 301)" > } > } > refinement.ncs { > find_automatically = False > restraint_group { > reference = chain A and resid 133:203 > selection = chain B and resid 133:203 > selection = chain C and resid 133:203 > selection = chain X and resid 133:203 > selection = chain Y and resid 133:203 > selection = chain Z and resid 133:203 > } > restraint_group { > reference = chain B and (resid 4:132 or resid 301) > selection = chain A and (resid 4:132 or resid 301) > selection = chain C and (resid 4:132 or resid 301) > selection = chain X and (resid 4:132 or resid 301) > selection = chain Y and (resid 4:132 or resid 301) > selection = chain Z and (resid 4:132 or resid 301) > } > } > refinement.output.prefix=3.6-tlsnter-indsite-inputb-autowght-ncs > -------------------- Parameters -------------------------- > > ------------------- Nathaniel Echols Lawrence Berkeley Lab 510-486-5136 NEchols(a)lbl.gov

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Re: [phenixbb] fwd: kicked maps
by Pavel Afonine 07 Mar '09

07 Mar '09

Hi Maia, I think it's easier to try out and have an answer right away rather than speculate. Why don't you just try and see if it helps? I can't tell in advance if it will help or not. Again, a "average kick map" (AKM) is computed as following: we create a large ensemble of structures (~500 structures) that are all randomly shaken. The shake amount (rmsd distortion introduced to coordinates) varies from 0 to 1.0A. Then for each structure the map is computed (mFo-DFc or 2mFo-DFc or any other requested by the user). And finally, all maps are averaged out to produce one "averaged kick map". Obviously, just from general considerations, such map is supposed to have less or no bias, less noise and enhanced signal, and potentially can clear up some initially bad densities. I would also try an "omit AKM", where you remove some model parts in questions and compute mFo-DF and 2mFo-DFc AK maps. Please use the latests CCI Apps for this since we recently fixed a number of problems with this. Pavel. >> Hi Pavel, I have a problem with long linkers between domains in a >> protein structure that is a biological hexamer. >> I don't have much density for the linkers. Should "kicked maps" help >> me to see the density? The resolution of the X-ray data is 2.3A. >> >> Maia >

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default bondlengths - metal
by Engin Ozkan 06 Mar '09

06 Mar '09

Hi, all, Recently following the phenixbb, I was made aware of phenix.metal_coordination. So I just gave it a try for a structure of mine with sodium in it. Specifically, I decided to turn the use-default-bondlengths option on. The result was surprising, because the output file thinks that sodum to oxygen distances are supposed to be 1.9 Angstroms. Work done by Marjorie Harding and others have shown that this distance should be about 2.4 (Acta Cryst. D62 (2006), 678-682; for a summary of their numbers, http://tanna.bch.ed.ac.uk/newtargs_06.html). I wonder why phenix.metal_coordination chose 1.9 A as the default Na-O distance, or is the default option a different type of bond distance, I am not sure. Any clarification from the authors would be appreciated. Below is part of the output, showing the distance: refinement.geometry_restraints.edits { bond { action = *add atom_selection_1 = name NA and chain N and resname NA and resseq 1 atom_selection_2 = name O and chain A and resname PHE and resseq 76 distance_ideal = 1.920420 sigma = 0.01 } } Engin

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fwd: phenix.autobuild- multiple models.
by Nathaniel Echols 04 Mar '09

04 Mar '09

> (The server bounced this message for some reason.) > From: Michael Karl Uhl <michael.uhl(a)uni-graz.at> > Date: March 3, 2009 11:55:16 PM PST > To: phenixbb(a)phenix-online.org > Subject: phenix.autobuild- multiple models > Reply-To: michael.uhl(a)a-b.at > > > Hello, > > I have not registered for this list until now, but have a very > urgent question concerning phenix.autobuild and multiple models as > input. Is there a possibility to merge models generated by different > phenix.autobuild runs. I have several overall_best-structure and > want to merge them into one single overall_best structure. I have > found the keyword "merge_models= True" but it does not really work > (Sorry, unknown file or keyword: merge_models=True). How should I > make the input in this case? > > > Thanks a lot, > > > Michael Uhl. > > ------------------- Nathaniel Echols Lawrence Berkeley Lab 510-486-5136 NEchols(a)lbl.gov

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Re: [phenixbb] Please help with neutron composite SA-omit
by Pavel Afonine 03 Mar '09

03 Mar '09

Hi Anna, a "kick map" is computed as following: we create a large ensemble of structures (~500 structures) that are all randomly shaken. The shake amount (rmsd distortion introduced to coordinates) varies from 0 to 1.0A. Then for each structure the map is computed (mFo-DFc or 2mFo-DFc or any other requested by the user). And finally, all maps are averaged out to produce one "averaged kick map". Obviously, such map is supposed to have less or no bias, less noise, and potentially can clear up some initially bad densities. The is currently no paper published about this method; we are preparing the manuscript. There are scattered references and uses of AK maps, mostly by Dusan Turk (he originally implemented it in his program MAIN). Documentation is not yet updated, this is true. Sorry. In phenix.refine GUI you can just check the corresponding box to compute a kick map (under map menu). In command line version you need to supply a parameter file that will define such map: refinement.electron_density_maps { map { mtz_label_amplitudes = 2FOFCWT mtz_label_phases = PH2FOFCWT likelihood_weighted = True obs_factor = 2 calc_factor = 1 kicked = True fill_missing_f_obs_with_weighted_f_model = True } map { mtz_label_amplitudes = FOFCWT mtz_label_phases = PHFOFCWT likelihood_weighted = True obs_factor = 1 calc_factor = 1 kicked = True fill_missing_f_obs_with_weighted_f_model = True } } I was recently trying this with neutron maps and the maps are significantly better (computed with AK approach). Please use the latest version of CCI Apps for this. Let me know if you have any questions or problems. Pavel. On 2/24/09 7:58 AM, Anna Gardberg wrote: > Hi, Pavel. > > I'm not trying to bring up features, exactly, but rather trying to get > an unbiased, quantitative measure of the the deuterium atoms' nuclear > density. The idea is to compare the visibility of hydrogen or > deuterium atoms with x-ray and neutron diffraction, correlating this > parameter (perhaps in the form of OMIT density) to others. > > I have only briefly toyed with kick-maps, but the lack of > documentation (http://phenix-online.org/documentation/refinement.htm > doesn't say much about how best to use them) made it frustrating. Can > you recommend an article about kick maps? Or some suggestions on how > to best use this feature, please? > > > -Anna > > On Mon, Feb 23, 2009 at 11:46 PM, Pavel Afonine <PAfonine(a)lbl.gov> wrote: > >> Hi Anna, >> >> you can ask phenix.refine produce "kick maps" that are supposed to be less >> biased, contain less noise and, if you are lucky, might bring some more >> features (that were buried in noise before). >> >> Let me know if you have any questions. >> >> Pavel. >> >> >> On 2/23/09 11:40 AM, Anna Gardberg wrote: >> >>> Hello. >>> >>> I am attempting to create an SA-omit composite map with neutron >>> scatterers. >>> >>> Unfortunately, >>> >>> phenix.autobuild data= "neutron.mtz" model="neutron_004.pdb" >>> composite_omit_type=sa_omit scattering_table=neutron >>> >>> results in an error: >>> >>> "Sorry, unknown file or keyword: scattering_table=neutron >>> Possibilities... (use 'phenix.autobuild --help all' to get full help): >>> general.resolve_pattern_command_list=neutron >>> density_modification.use_resolve_pattern=neutron >>> decision_making.semi_acceptable_r=neutron >>> decision_making.acceptable_r=neutron >>> multiple_models.multiple_models_starting_resolution=neutron >>> " >>> >>> Can someone here help, please? >>> >>> (For what it's worth: I'd use nCNS, but while CNS 1.21 (precompiled >>> binaries) works on my computer, CNS 1.1 version seems to compile, it >>> will not run. When I apply the nCNS patch to CNS 1.1, again it seems >>> to compile, but will not run. ) >>> >>> Regards, >>> Anna Gardberg >>> _______________________________________________ >>> phenixbb mailing list >>> phenixbb(a)phenix-online.org >>> http://www.phenix-online.org/mailman/listinfo/phenixbb >>> >>>

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AutoBuild after resolve
by Mo Wong 28 Feb '09

28 Feb '09

Hi all, Can someone tell me where in the AutoBuild GUI I can set "phases_from_resolve"? I've looked for it in the "set variable" section, but it's not listed. Thanks!

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rfree flag fractions
by Yusuf Akhter 28 Feb '09

28 Feb '09

Hi Everybody! I am using phenix version 1.3b for refining a structure at 3 A resolution and total number of total reflections are 12680. I have seen a provision in phenix to change the default maximal number of test flags to be generated and the fraction with this command line xray_data.r_free_flags.fraction=0.05 xray_data.r_free_flags.max_free=500 My queries are 1)when should somebody use this utility ?? 2)what is minimum number of Rfree flags one should use on this resolution and this total number of reflections?? Any kind of suggestions will be appreciated. Cheers! Yusuf

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RuntimeError: Not enough memory for cubicles:
by Gino Cingolani 27 Feb '09

27 Feb '09

Hi, I'm refining a huge structure with ~13,000 residues in the asymmetric unit. I started a massive job with the following inputs: phenix.refine data.mtz model.pdb ordered_solvent=true strategy=individual_sites+group_adp+tls tls_group_selections.params main.ncs=true main.number_of_macro_cycles=10 After >24 h the Rfree had dropped from 45% to 33%, but at the very end, just before outputting the refined pdb model, Phenix died with the following error message: ############################################################ Hello all========== residual map mFobs-DFmodel: highest peaks and deepst holes ========= ----------peaks---------- Traceback (most recent call last): File "/usr/local/phenix-1.3-final/phenix/phenix/command_line/refine.py", line 5, in <module> command_line.run(command_name="phenix.refine", args=sys.argv[1:]) File "/usr/local/phenix-1.3-final/phenix/phenix/refinement/command_line.py", line 89, in run call_back_after_monitor_collect=call_back_after_monitor_collect) File "/usr/local/phenix-1.3-final/phenix/phenix/refinement/driver.py", line 1081, in run call_back_after_monitor_collect = call_back_after_monitor_collect) File "/usr/local/phenix-1.3-final/phenix/phenix/refinement/strategies.py", line 724, in refinement_machine fmodels=fmodels, model=model, log=log) File "/usr/local/phenix-1.3-final/phenix/phenix/refinement/strategies.py", line 752, in highest_peaks_and_deepest_holes_in_residual_map log = log) File "/usr/local/phenix-1.3-final/mmtbx/mmtbx/find_peaks.py", line 210, in show_highest_peaks_and_deepest_holes log = log) File "/usr/local/phenix-1.3-final/mmtbx/mmtbx/find_peaks.py", line 117, in __init__ map = fft_map_data).all(max_clusters = max_number_of_peaks) File "/usr/local/phenix-1.3-final/cctbx/cctbx/maptbx/__init__.py", line 196, in peak_search max_clusters=parameters.max_clusters()) File "/usr/local/phenix-1.3-final/cctbx/cctbx/maptbx/__init__.py", line 303, in __init__ general_positions_only=self._general_positions_only) File "/usr/local/phenix-1.3-final/cctbx/cctbx/crystal/__init__.py", line 477, in site_cluster_analysis cubicle_epsilon=cubicle_epsilon) RuntimeError: Not enough memory for cubicles: This may be due to unreasonable parameters: cubicle_edge=0.7 space_span=(293.298,92.903,214.527) n_cubicles=(419,133,307) max_number_of_bytes=1724676096 ###################################################### Any suggestion on what to do? As invididual refinement modules (e.g. regular rigid body refinemnet, SA, energy minimization, TLS, etc) run OK, is the problem coming from the "ordered_solvent=true" command? Thanks in advance! Gino Cingolani, Ph.D. *********************************************************** Gino Cingolani, Ph.D. Assistant Professor Dept. of Biochemistry and Molecular Biology SUNY Upstate Medical University 750 E. Adams Street, Syracuse, NY, 13210 Tel. (315) 464 8744 Fax. (315) 464 8750 Email: cingolag(a)upstate.edu *********************************************************** "Nati non foste per viver come bruti, ma per seguir virtute e conoscenza" ("You were not born to live like brutes, but to follow virtue and knowledge") Dante, The Divine Comedy (Inferno, XXVI, vv. 119-120)

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Failed to carry out AutoBuild_parallel_omit
by Jhon Thomas 26 Feb '09

26 Feb '09

Hello all There is a problem with running phenix.autobuild. Failed to carry out AutoBuild_parallel_omit: child process stderr output: command: 'csh /home/thomas/phenix_omitmap/AutoBuild_run_1_/TEMP0/RUN_FILE_1' Badly placed ()'s. What could be solution. Thanks Thomas

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resolve.phenix and helices_strands_only
by Mo Wong 25 Feb '09

25 Feb '09

Hi all, I'm sure I've done this before, but could some please let me know/remind me what the correct syntax is for including "helices_strands_only=True" in a resolve script like the one below? phenix.resolve<<EOD hklin solve.mtz labin FP=FP SIGFP=SIGFP PHIB=PHIB FOM=FOM HLA=HLA HLB=HLB HLC=HLC HLD=HLD solvent_content 0.43 database 5 EOD Thanks!

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Select atoms by B-factors?
by Oliver Clarke 25 Feb '09

25 Feb '09

Hi, I'm currently refining a structure at 1.6A. Substantial portions of the structure are very well ordered, with B-factors < 15. I'd like to refine these well ordered regions using anisotropic thermal parameters, while keeping everything else isotropic. However, in doing so, the atom selections tend to become quite convoluted. Is there any way to select all atoms which initially have an isotropic B less than a certain cuttoff value? That way one could (after isotropic B-factor refinement) select the most ordered regions of the structure for anisotropic refinement. Cheers, Oliver Clarke

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links and REMARK 3 record in the final PDB
by Pascal Egea 24 Feb '09

24 Feb '09

Dear All, I apologize if this question has already been answered. I am refining a structure of a glycosylated-enzyme and I understood the way to define all the links (N-glycosylation to the ASN and beta-glycosidic bonds between the NAG units) and refinement is complete and everything is good. All the links I included in my cif_link definition file where taken into account and dealt with by Phenix (the .def and .geo files are fine). Is it normal however that in the resulting refined PDB file, no such links are written by PHENIX under the REMARK 3 record ? Same thing for the 5 disulfide bonds present in the protein. Thanks in advance for the clarification. Pascal Egea University of California San Francisco Department of Biochemistry and Biophysics Laboratory of Robert Stroud

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Please help with neutron composite SA-omit
by Anna Gardberg 24 Feb '09

24 Feb '09

Hello. I am attempting to create an SA-omit composite map with neutron scatterers. Unfortunately, phenix.autobuild data= "neutron.mtz" model="neutron_004.pdb" composite_omit_type=sa_omit scattering_table=neutron results in an error: "Sorry, unknown file or keyword: scattering_table=neutron Possibilities... (use 'phenix.autobuild --help all' to get full help): general.resolve_pattern_command_list=neutron density_modification.use_resolve_pattern=neutron decision_making.semi_acceptable_r=neutron decision_making.acceptable_r=neutron multiple_models.multiple_models_starting_resolution=neutron " Can someone here help, please? (For what it's worth: I'd use nCNS, but while CNS 1.21 (precompiled binaries) works on my computer, CNS 1.1 version seems to compile, it will not run. When I apply the nCNS patch to CNS 1.1, again it seems to compile, but will not run. ) Regards, Anna Gardberg

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Re: [phenixbb] Please help with neutron composite SA-omit
by Thomas C. Terwilliger 23 Feb '09

23 Feb '09

Hi again Anna, Can you possibly try this syntax for the "refine.eff" file: refinement{ main {scattering_table=neutron} } and then say phenix.autobuild <your usual parameters> refine_eff_file=refine.eff That should do it! All the best, -Tom T > Hello. > > I am attempting to create an SA-omit composite map with neutron > scatterers. > > Unfortunately, > > phenix.autobuild data= "neutron.mtz" model="neutron_004.pdb" > composite_omit_type=sa_omit scattering_table=neutron > > results in an error: > > "Sorry, unknown file or keyword: scattering_table=neutron > Possibilities... (use 'phenix.autobuild --help all' to get full help): > general.resolve_pattern_command_list=neutron > density_modification.use_resolve_pattern=neutron > decision_making.semi_acceptable_r=neutron > decision_making.acceptable_r=neutron > multiple_models.multiple_models_starting_resolution=neutron > " > > Can someone here help, please? > > (For what it's worth: I'd use nCNS, but while CNS 1.21 (precompiled binaries) works on my computer, CNS 1.1 version seems to compile, it will not run. When I apply the nCNS patch to CNS 1.1, again it seems to compile, but will not run. ) > > Regards, > Anna Gardberg > _______________________________________________ > phenixbb mailing list > phenixbb(a)phenix-online.org > http://www.phenix-online.org/mailman/listinfo/phenixbb >

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Re: [phenixbb] Please help with neutron composite SA-omit
by Thomas C. Terwilliger 23 Feb '09

23 Feb '09

Hi Anna, Try putting your cmmand "scattering_table=neutron" in a "refine.eff" file and then run phenix.autobuild including the keyword refine_eff_file=refine.eff (note that you may need to specify the scope of scattering_table just as if you were using the command directly for phenix.refine) That is the way you can put any phenix.refine parameters into autobuild. Let me know if that doesn't do it! -Tom T > Hello. > > I am attempting to create an SA-omit composite map with neutron > scatterers. > > Unfortunately, > > phenix.autobuild data= "neutron.mtz" model="neutron_004.pdb" > composite_omit_type=sa_omit scattering_table=neutron > > results in an error: > > "Sorry, unknown file or keyword: scattering_table=neutron > Possibilities... (use 'phenix.autobuild --help all' to get full help): > general.resolve_pattern_command_list=neutron > density_modification.use_resolve_pattern=neutron > decision_making.semi_acceptable_r=neutron > decision_making.acceptable_r=neutron > multiple_models.multiple_models_starting_resolution=neutron > " > > Can someone here help, please? > > (For what it's worth: I'd use nCNS, but while CNS 1.21 (precompiled > binaries) works on my computer, CNS 1.1 version seems to compile, it > will not run. When I apply the nCNS patch to CNS 1.1, again it seems > to compile, but will not run. ) > > Regards, > Anna Gardberg > _______________________________________________ > phenixbb mailing list > phenixbb(a)phenix-online.org > http://www.phenix-online.org/mailman/listinfo/phenixbb >

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DTT at special position
by Nikos Pinotsis 23 Feb '09

23 Feb '09

Dear all, even though I checked the documentation and previous threads I didn't find something relative to my problem: I have an elongated e-density that looks like DTT and appears to be located on a special position (there is actually an axis betwenn C2 and C3 atoms of DTT). Refining with phenix.refine using either 0.5 or 1.0 occupancy, I am getting the DTT molecule outside the density (and the symmetry related DTT from the other side and still in the middle the strong difference density. thanks in advance for any suggestions-solutions Nikos -- --------------------------------- Dr. Nikos Pinotsis Section of Structural Biology Institute of Cancer Research Chester Beatty Laboratories 237 Fulham Road London SW3 6JB, UK Tel: +44 20 7153 5453 / 5447 --------------------------------- The Institute of Cancer Research: Royal Cancer Hospital, a charitable Company Limited by Guarantee, Registered in England under Company No. 534147 with its Registered Office at 123 Old Brompton Road, London SW7 3RP. This e-mail message is confidential and for use by the addressee only. If the message is received by anyone other than the addressee, please return the message to the sender by replying to it and then delete the message from your computer and network.

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ADP refinement
by Katya Heldwein 20 Feb '09

20 Feb '09

Hi, I would like to use TLS refinement for protein (I have selected TLS groups) and individual isotropic refinement for water. How can I specify this in phenix.refine? Thanks, Katya -- Ekaterina Heldwein, Ph.D. Assistant Professor Department of Molecular Biology and Microbiology Tufts University School of Medicine 136 Harrison Ave Boston, MA 02111 phone: 617-636-0858 fax: 617-636-0337 e-mail: katya.heldwein(a)tufts.edu

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Strange negative density when refining at low resolution
by Andrew Purkiss-Trew 20 Feb '09

20 Feb '09

Dear Phenixers I've been helping a colleague with a dataset at ~3.8 Angstroms (phases and map from AutoSharp using SAD phasing). At the moment he has an incomplete polyALA model consisting of two chains related by NCS and a few extra sections. Refinement seems to proceed OK using phenix.refine version 1.4-3, but the resultant maps have blobs of negative density in the core of the protein. I am assuming that these are a side-effect of the bulk-solvent correction part of the refinement which is confusing the region where the protein sidechains would be as solvent. There are no corresponding negative peaks on the surface of protein, but some positive peaks where larger sidechains may be. Is this interpretation likely to be correct and if so, which parameter should be altered in the Bulk Solvent section of the input to allow for a bigger mask around the protein. I see that it isn't recommended to change the parameters, but the refinement.mask.solvent_radius=1.0 looks like an obvious candidate. If necessary, I can get an image made showing the maps. Thanks Andrew Purkiss-Trew This communication is from Cancer Research UK. Our website is at www.cancerresearchuk.org. We are a charity registered under number 1089464 and a company limited by guarantee registered in England & Wales under number 4325234. Our registered address is 61 Lincoln's Inn Fields, London WC2A 3PX. Our central telephone number is 020 7242 0200. This communication and any attachments contain information which is confidential and may also be privileged. It is for the exclusive use of the intended recipient(s). If you are not the intended recipient(s) please note that any form of disclosure, distribution, copying or use of this communication or the information in it or in any attachments is strictly prohibited and may be unlawful. If you have received this communication in error, please notify the sender and delete the email and destroy any copies of it. E-mail communications cannot be guaranteed to be secure or error free, as information could be intercepted, corrupted, amended, lost, destroyed, arrive late or incomplete, or contain viruses. We do not accept liability for any such matters or their consequences. Anyone who communicates with us by e-mail is taken to accept the risks in doing so.

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