- phenixbb - phenix-online.org

BEAM TIME AVAILABLE FOR MACROMOLECULAR CRYSTALLOGRAPHY
by Cyndi Salbego 28 May '08

28 May '08

BEAM TIME AVAILABLE FOR MACROMOLECULAR CRYSTALLOGRAPHY AT THE TWO ID BEAMLINES OF NE-CAT AT APS. Beamline 24ID-C: Variable energy between 6-18keV, ADSC Q315 Detector, MAD Capable. Focused beam size 20x80micron Beamline 24ID-E: Equipped with MD2 microdiffractometer, delivering beam as small as 5 microns. Single energy (12662eV), ADSC Q315 Detector. Contact csalbego(a)anl.gov for further details. See http://necat.chem.cornell.edu for information on our beamlines and a calendar of available days.

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syntax and alternate conformations
by Mark Collins 28 May '08

28 May '08

Hi I have an unexpected result, my syntax must be incorrect. The relevant script commands are below, the problem is residues A113 and B143 have alternate conformation occupancies that sums to 0.98 to 1.06 respectively. Clearly alternate conformations of a single residue should sum to 1 (or less than 1 possibly). Any suggestions please? Thank you, Mark refine { strategy = *individual_sites \ rigid_body \ *individual_adp \ group_adp \ tls \ individual_occupancies \ *group_occupancies \ group_anomalous \ occupancies { individual = None group = chain A and resid 113 and altid A group = chain A and resid 113 and altid B group = chain B and resid 143 and altid A group = chain B and resid 143 and altid B } }

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Re: [phenixbb] problem with high Rfree
by Christina Bourne 28 May '08

28 May '08

Thank you very much for your help. I just wanted to follow up in how I'm progressing with this. I tried the things you suggested, as well as a variety of others, with no luck. It turns out that my 4mol/AU P41 twinned data is ACTUALLY 8mol/AU P212121. The packing in the AU has an almost 41 screw relating 4 mols to the other 4. When this operation is carried out, 2 mols overlay 2 others almost perfect, while the other 2 overlay the other 2 by 180 degrees. So my AU packing is a pseudo-41 with apparent twinning. (The b dimension did not need halving, so my cell is 2x the size, if that makes sense). The data refines very well as P212121, and Rfree drops like a rock. Again, thank you so much for your suggestions, and Phenix is really wonderful! Christina ----- Original Message ---- From: Pavel Afonine <pafonine(a)lbl.gov> To: PHENIX user mailing list <phenixbb(a)phenix-online.org> Sent: Tuesday, May 20, 2008 1:51:42 AM Subject: Re: [phenixbb] problem with high Rfree Hi Christina, I usually observe similar R/Rfree behavior when I use LS target instead of maximum-likelihood. In fact, twin refinement in phenix.refine is based on LS target function. This is just to share my observations; it's not necessarily happening in your case. - How many of test reflections you have and how they are distributed in resolution bins? - Just out of curiosity: did you try to ignore twinning and run refinement with default target? - What if you don't run SA? - Did you try to play with target weights (try different values for wxc_scale and wxu_scale) to see how this affect the R-factors? - Are you using the latest (or one of) phenix.refine? - Did you try to fill in water? Could you send a log file: may be we could spot something outstanding... Pavel. On 5/19/2008 1:32 PM, Christina Bourne wrote: Hello BB, I am working on a structure that is twinned (merohedral) in P41. Initial estimates of twinning fraction (via xtriage and Yeates server) are around 0.37; in refinement they start around 0.49 and drop to 0.46 (so far). My MR soln is good (Phaser LLG ~550) with 4 mols per AU; this gives good packing with no room for another mol. I have data from 48-2.8A. I should mention that data processing wasn't easy- this crystal form also has an apparent epitaxial twin in the b dimension causing a doubling in that dimension. During indexing (with SAINT) I applied a transformation of 100 00.50 001 to the reflections, which then gave me the expected cell and from Xprep the data looks OK. (Yes, I am trying to grow different forms) Maps look nice, although I wish my ligand had more/better density. I ran phenix.refine with defaults, and included twin_law="h,-k,-l", xray_data.r_free_flags.generate=true, detwin.map_types.aniso_correct=true and also simulated_annealing=true. My starting R/ Rfree is 0.448/ 0.4385; ending is 0.2962/ 0.4270. Geometry is somewhat tighter after refinement but is better (bonds 0.017 to 0.01, angles 1.966 to 1.530). I have not included my ligand, and I can see a few spots where the model needs adjusting, but nothing majorly wrong. Why is my Rfree hanging so high? Is it becaues I have bad karma? Is it to do with the twinning? I am pretty sure my space group is right (based on the above info and the maps look fine; Phaser could not find a solution in P43). There isn't room for anything else in the cell. Any opinions or suggestions are most welcome as I wait for better xtals to grow... Thanks in advance, Christina ________________________________ _______________________________________________ phenixbb mailing list phenixbb(a)phenix-online.org http://www.phenix-online.org/mailman/listinfo/phenixbb

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OXT
by Rife, Christopher L 23 May '08

23 May '08

Should phenix.refine be able to handle OXT? I find it is moving the OXT atom ~2A from where it should be. Do I need to rename it or add a separate definition to the refinement? Thanks, Chris

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IUCr Crystallographic Computing School 2008
by Ralf W. Grosse-Kunstleve 23 May '08

23 May '08

IUCr Crystallographic Computing School 2008 * Sharing our knowledge * Kyoto, Japan, August 18-23 http://www.iucr.org/iucr-top/comm/ccom/kyoto2008/program.html The IUCr Crystallographic Computing School 2008 school aims to bring together both computational methods developers and users interested in looking beyond the interface. The format of the school fosters exchange of ideas via formal lectures, afternoon tutorials, coding challenges and code comparison sessions. The world-wide crystallographic community (including macro- and small-molecule crystallography, powder diffraction, and small-angle scattering) is invited to an intensive session of working together and learning from each other. The schedule of the program is available via the web link above. Abstracts are being added. Thanks to support from sponsors, we have been able to keep the registration cost (including accommodation and meals) below 70,000 YEN (ca. 430 EUR, 665 USD). The number of attendees is limited to 80 students. For more information visit the web site above. The registration deadline is July 25th, 2008. Organizing committee: A. L. Spek (Utrecht University , Netherlands) R. Grosse-Kunstleve (LBNL, USA) M. Yao (Hokkaido University, Japan) A. Nakagawa (Osaka Institute of Protein, Japan) H. Powell (MRC, UK) L. Cranswick (NRC , Canada)

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Shell variable SSH_Path not set
by shivesh kumar 23 May '08

23 May '08

Dear all, We have installed Phenix in Red Hat Linux enterprises 5. It takes a long time for the GUI to appear with the following message-- Shell variable SSH_Path not set What is the solution of this problem. Thanx in advance for suggestions. shivesh

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NCS restraints
by Rife, Christopher L 22 May '08

22 May '08

I'm refining a twinned structure at 2.2A that has 6 copies in the ASU. I am using NCS, however the ncs restraints are so tight that they are keeping the chains identical even though this takes them out of the density. Are there any parameters I can adjust that will lessen the strength of these restraints? Taking away NCS completely is also not ideal. I guess I would like an equivalent of 'medium' or 'loose' NCS restraints as implemented in Refmac. Thanks, Chris

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Re: [phenixbb] Any real space map-mask / NCS utility?
by Tom Terwilliger 22 May '08

22 May '08

Hi Partha, I think we don't have a tool for just what you want...but here is an idea given what you are trying: In coot build a short piece of polypeptide in the region where one ha site is located. Match the map in some way. Now rotate/translate this exact piece of chain over to your other sites and match the density there. Now use phenix.superpose_pdbs to find your ncs and put that in resolve. Good luck! -Tom t At 05:48 AM 5/22/2008, you wrote: >Hi, > >Apologies for the strange question. > >Since phenix has one fantastic tool for each kind of purpose, I was >wondering if there is something that could combine features of USF >Rave package for example.. basically the question arises from the >difficulty of finding NCS operators in some cases, if we have less >than three heavy atoms per molecule or map is too bad to build >something. > >I am trying to create a mask around a heavy atom site in the map, give >it a translation to the next heavy atom which is probably in the next >molecule, give a 6d rotation and use that in Resolve for NCS >averaging. > >Any suggestion / script would be greatly appreciated. > >Cheers, Partha > > >-- >MRC National Institute for Medical Research >Division of Molecular Structure >The Ridgeway, NW7 1AA, UK >Email: pchakra(a)nimr.mrc.ac.uk >Phone: + 44 208 816 2515 >_______________________________________________ >phenixbb mailing list >phenixbb(a)phenix-online.org >http://www.phenix-online.org/mailman/listinfo/phenixbb Thomas C. Terwilliger Mail Stop M888 Los Alamos National Laboratory Los Alamos, NM 87545 Tel: 505-667-0072 email: terwilliger(a)LANL.gov Fax: 505-665-3024 SOLVE web site: http://solve.lanl.gov PHENIX web site: http:www.phenix-online.org ISFI Integrated Center for Structure and Function Innovation web site: http://techcenter.mbi.ucla.edu TB Structural Genomics Consortium web site: http://www.doe-mbi.ucla.edu/TB

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Any real space map-mask / NCS utility?
by Partha Chakrabarti 22 May '08

22 May '08

Hi, Apologies for the strange question. Since phenix has one fantastic tool for each kind of purpose, I was wondering if there is something that could combine features of USF Rave package for example.. basically the question arises from the difficulty of finding NCS operators in some cases, if we have less than three heavy atoms per molecule or map is too bad to build something. I am trying to create a mask around a heavy atom site in the map, give it a translation to the next heavy atom which is probably in the next molecule, give a 6d rotation and use that in Resolve for NCS averaging. Any suggestion / script would be greatly appreciated. Cheers, Partha -- MRC National Institute for Medical Research Division of Molecular Structure The Ridgeway, NW7 1AA, UK Email: pchakra(a)nimr.mrc.ac.uk Phone: + 44 208 816 2515

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decrease number of refs in test set
by Mark A Saper 22 May '08

22 May '08

I have a data set with about 10% of the reflections in the test set. I want to retain this test set for further refinement in phenix, but I want to decrease the number of reflections to say 5%. Can this be done in phenix? Thanks, Mark _________________________________ Mark A. Saper, Ph.D. Associate Professor, Biophysics and Department of Biological Chemistry University of Michigan 3040 Chemistry Building 930 N University Ave Ann Arbor MI 48109-1055 saper(a)umich.edu phone (734) 764-3353 fax (734) 764-3323 Research summary

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phenix.twin_map_utils gives AttributeError: 'module' object has no attribute 'r_free_flags_params'
by Francis E Reyes 21 May '08

21 May '08

chem171-152-dhcp:exptl_fobs_phases_freeR_flags.mtz francisreyes$ phenix.twin_map_utils xray_data.file=exptl_fobs_phases_freeR_flags.mtz model=MR.1_pdbset1_refine_007.pdb unit_cell=73.5,73.5,114,90,90,90 space_group="P 41 21 2" twin_utils { input { unit_cell = 73.5 73.5 114 90 90 90 space_group = "P 41 21 2" xray_data { file_name = "exptl_fobs_phases_freeR_flags.mtz" obs_labels = None free_flag = None } model { file_name = "MR.1_pdbset1_refine_007.pdb" } } parameters { twinning { twin_law = None max_delta = 3 } } output { logfile = "twin_tools.log" map_coeffs_root = "MAP_COEFFS" obs_and_calc = "obs_and_calc.mtz" } } Traceback (most recent call last): File "/usr/local/phenix-1.3b-rc5/mmtbx/mmtbx/command_line/ twin_map_utils.py", line 7, in <module> twin_map_utils.run(args=sys.argv[1:]) File "/usr/local/phenix-1.3b-rc5/mmtbx/mmtbx/twinning/ twin_map_utils.py", line 256, in run tmp_params = utils.r_free_flags_params.extract() AttributeError: 'module' object has no attribute 'r_free_flags_params' Any 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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phaser_x.mtz, resolve_x.mtz and exptl_fobs_phases_freeR_flags.mtz give different Rfree's using same model?
by Francis E Reyes 20 May '08

20 May '08

Ok. I think I have a case where I can't refine unless I use density modified experimental phases. I did an autosol run where I specified build=False so I don't have an exptl_fobs_phases_freeR_flags.mtz, but I do have phaser_1.mtz and resolve_1.mtz. However, when I refine my model using mlhl my Rfree drops below 30 when using resolve_x.mtz and not phaser_x.mtz nor using the original d*trek ref using the same model? Using any of the other mtz's results in Rfree's in the mid 30s. Interestingly refining against the original d*trek results in an increase of Rfree with macro cycle? I checked the log file for resolve_x.mtz and although it says it's using the mlhl refinement target, it seems to be using FP, SIGFP (not the HL coefficients that I thought phased refinement would use) as evidenced by the .log file under 'Non-default parameters'. In this section it doesn't read in the HL cofficients? Is there any indication that it's actually refining against the phases? Any insight as to which mtz to use for final refinement would be suggested. Thanks FR P.S. What is the refinement target ml_sad? --------------------------------------------- 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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problem with high Rfree
by Christina Bourne 20 May '08

20 May '08

Hello BB, I am working on a structure that is twinned (merohedral) in P41. Initial estimates of twinning fraction (via xtriage and Yeates server) are around 0.37; in refinement they start around 0.49 and drop to 0.46 (so far). My MR soln is good (Phaser LLG ~550) with 4 mols per AU; this gives good packing with no room for another mol. I have data from 48-2.8A. I should mention that data processing wasn't easy- this crystal form also has an apparent epitaxial twin in the b dimension causing a doubling in that dimension. During indexing (with SAINT) I applied a transformation of 100 00.50 001 to the reflections, which then gave me the expected cell and from Xprep the data looks OK. (Yes, I am trying to grow different forms) Maps look nice, although I wish my ligand had more/better density. I ran phenix.refine with defaults, and included twin_law="h,-k,-l", xray_data.r_free_flags.generate=true, detwin.map_types.aniso_correct=true and also simulated_annealing=true. My starting R/ Rfree is 0.448/ 0.4385; ending is 0.2962/ 0.4270. Geometry is somewhat tighter after refinement but is better (bonds 0.017 to 0.01, angles 1.966 to 1.530). I have not included my ligand, and I can see a few spots where the model needs adjusting, but nothing majorly wrong. Why is my Rfree hanging so high? Is it becaues I have bad karma? Is it to do with the twinning? I am pretty sure my space group is right (based on the above info and the maps look fine; Phaser could not find a solution in P43). There isn't room for anything else in the cell. Any opinions or suggestions are most welcome as I wait for better xtals to grow... Thanks in advance, Christina

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Can't autobuild after autosol?
by Francis E Reyes 20 May '08

20 May '08

******************************************************************************** Failed to carry out AutoBuild_start: Sorry, 'after_autosol' is set, but there were not any solutions from AutoSol found...please make sure that the highest-numbered AutoSol run is a completed run (you can use 'phenix.autosol show_runs' to see what runs are present and 'phenix.autosol delete_runs=xx' to remove any incomplete runs) ******************************************************************************** when issues with phenix.autobuild after_autosol phenix.autosol show_runs gives.. ------------------------------------------------------------ Starting AutoSol with the command: phenix.autosol display_runs=True --------------------------------------------------------------------------- List of runs for AutoSol Run Title / Notes --------------------------------------------------------------------------- --------------------------------------------------------------------------- 3: Run 3 AutoSol Fri May 16 13:10:11 2008 STEP: finished Top solution: # 2 Dataset #1 Score: 27.84 FOM: 0.29 Built: 121 Side-chains: 0 Chains: 21 CC: 0.45 Sites: 4 Score type: CC RFACTOR SKEW FOM NCS_OVERLAP Raw scores: 0.61 0.59 0.03 0.30 0.00 Z-scores: 14.84 5.76 1.26 5.98 0.00 --------------------------------------------------------------------------- Does that mean an autosol run has completed? 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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Tell phenix.autosol to find more heavy atoms?
by Francis E Reyes 19 May '08

19 May '08

I have a SAD map which is beautiful, but I want to look for more heavy atoms before further refinement... Would the proper procedure be.... SAD dataset, reading heavy-atom sites from a PDB file written by phenix.hyss: phenix.autosol 11 Pb data=deriv.sca seq_file=seq.dat \ sites_file=deriv_hyss_consensus_model.pdb This will carry out the usual structure solution process, but will read sites from deriv_hyss_consensus_model.pdb, try both hands, and carry on from there. If you know the hand of the substructure, you can fix it with have_hand=True. Would there be a PDS friendly way to do this (not necessary though) ? i.e. phenix.autobuild after_autosol --------------------------------------------- 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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Problem starting TLS refinement
by Jendrek 16 May '08

16 May '08

Hi, I would like to do TLS but every time I try to start it I get following error: File "/usr/local/cci_apps/cci_apps_sources/phenix/phenix/command_line/refine.py", line 5, in <module> command_line.run(command_name="phenix.refine", args=sys.argv[1:]) File "/usr/local/cci_apps-1421/cci_apps_sources/phenix/phenix/refinement/command_line.py", line 69, in run overwrite = command_line_interpreter.command_line.options.overwrite) File "/usr/local/cci_apps-1421/cci_apps_sources/phenix/phenix/refinement/driver.py", line 199, in __init__ value = 0.0) File "/usr/local/cci_apps-1421/cci_apps_sources/mmtbx/mmtbx/tls/tools.py", line 735, in generate_tlsos origins.append(xrs.center_of_mass()) File "/usr/local/cci_apps-1421/cci_apps_sources/cctbx/cctbx/xray/structure.py", line 943, in center_of_mass return self.sites_cart().mean_weighted(weights=atomic_weights) RuntimeError: mean_weighted() argument is an empty array I've attached my input file. Any suggestions on what I'm doing wrong would be greatly appreciated. Regards, Andrzej -- Andrzej LYSKOWSKI, Ph.D. (andrzej[.]lyskowski[(a)]helsinki[.]fi) Institute of Biotechnology - Structural Biology & Biophysics P. O. Box 65, Viikinkaari 1 FIN-00014 University of HELSINKI, FINLAND TEL.: 358 9 191 58955 FAX : 358 9 191 59940 # Default parameters for subsequent refinement # Date 2008-05-16 Time 18:33:47 EEST +0300 (1210952027.81 s) # Command to extract only non-defaults: # phenix.refine --diff-params "h135d-mg_007.def" refinement { crystal_symmetry { unit_cell = 70.31999969 173.0200043 54.97000122 90 90 90 space_group = "P 21 21 2" } input { pdb { file_name = "/Volumes/Xanthias_data/andrzej/xtal/tap_ccp4-h135d/3844/h135d-mg_006.pdb" } neutron_data { ignore_xn_free_r_mismatch = False file_name = None labels = None high_resolution = None low_resolution = None outliers_rejection = True sigma_fobs_rejection_criterion = 0 sigma_iobs_rejection_criterion = 0 ignore_all_zeros = True force_anomalous_flag_to_be_equal_to = None r_free_flags { file_name = None label = None test_flag_value = None disable_suitability_test = False ignore_pdb_hexdigest = False ignore_r_free_flags = False generate = False fraction = 0.1 max_free = 2000 lattice_symmetry_max_delta = 5 use_lattice_symmetry = True } } xray_data { file_name = "/Volumes/Xanthias_data/andrzej/xtal/tap_ccp4-h135d/3844/3844_refine_data.mtz" labels = "I-obs,SIGI-obs" high_resolution = None low_resolution = None outliers_rejection = True sigma_fobs_rejection_criterion = 0 sigma_iobs_rejection_criterion = 0 ignore_all_zeros = True force_anomalous_flag_to_be_equal_to = None r_free_flags { file_name = "/Volumes/Xanthias_data/andrzej/xtal/tap_ccp4-h135d/3844/3844_refine_data.mtz" label = "R-free-flags" test_flag_value = 1 disable_suitability_test = False ignore_pdb_hexdigest = False ignore_r_free_flags = False generate = False fraction = 0.05 max_free = 2000 lattice_symmetry_max_delta = 5 use_lattice_symmetry = True } } experimental_phases { file_name = "/Volumes/Xanthias_data/andrzej/xtal/tap_ccp4-h135d/3844/3844_refine_data.mtz" labels = "HLA,HLB,HLC,HLD" } monomers { file_name = None } symmetry_safety_check = *error warning } output { prefix = "h135d-mg" serial = 7 serial_format = "%03d" write_eff_file = True write_geo_file = True 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 } map { mtz_label_amplitudes = "2FOFCWT" mtz_label_phases = "PH2FOFCWT" likelihood_weighted = True obs_factor = 2 calc_factor = 1 } map { mtz_label_amplitudes = "FOFCWT" mtz_label_phases = "PHFOFCWT" likelihood_weighted = True obs_factor = 1 calc_factor = 1 } anomalous_difference_map { mtz_label_amplitudes = "ANOM" mtz_label_phases = "PHANOM" } grid_resolution_factor = 0.3333333333 region = *selection cell atom_selection = None atom_selection_buffer = 3 apply_sigma_scaling = True apply_volume_scaling = False } refine { strategy = *individual_sites rigid_body *individual_adp group_adp *tls \ occupancies group_anomalous sites { individual = None rigid_body = "chain A" rigid_body = "chain B" } adp { individual { isotropic = all anisotropic = None } group = None one_adp_group_per_residue = True tls = "(chain A and resid 030:060)" tls = "(chain A and resid 061:135)" tls = "(chain A and resid 136:165)" tls = "(chain A and resid 166:190)" tls = "(chain A and resid 191:244)" tls = "(chain A and resid 245:307)" tls = "(chain A and resid 308:328)" tls = "(chain A and resid 329:375)" tls = "(chain B and resid 030:060)" tls = "(chain B and resid 061:135)" tls = "(chain B and resid 136:165)" tls = "(chain B and resid 166:190)" tls = "(chain B and resid 191:244)" tls = "(chain B and resid 245:307)" tls = "(chain B and resid 308:328)" tls = "(chain B and resid 329:375)" } occupancies { individual = None group = None one_occupancy_group_per_residue = False } anomalous_scatterers { group { selection = None f_prime = 0 f_double_prime = 0 refine = *f_prime *f_double_prime } } } main { bulk_solvent_and_scale = True simulated_annealing = False ordered_solvent = False ncs = False ias = False number_of_macro_cycles = 3 max_number_of_iterations = 12 use_form_factor_weights = False tan_u_iso = False use_convergence_test = False target = ml *mlhl ml_sad ls min_number_of_test_set_reflections_for_max_likelihood_target = 50 max_number_of_resolution_bins = 30 reference_xray_structure = None use_experimental_phases = None compute_optimal_errors = False random_seed = 3326496 scattering_table = wk1995 it1992 *n_gaussian neutron use_normalized_geometry_target = True target_weights_only = False use_f_model_scaled = False max_d_min = 0.25 fake_f_obs = False optimize_mask = False occupancy_max = 1 occupancy_min = 0.1 stir = None rigid_bond_test = False show_residual_map_peaks_and_holes = True fft_vs_direct = False outliers_rejection = True find_and_add_hydrogens = False } modify_start_model { selection = None adp { selection = None randomize = None set_b_iso = None convert_to_isotropic = None convert_to_anisotropic = None shift_b_iso = None scale_adp = None } sites { selection = None shake = None translate = "0" "0" "0" rotate = "0" "0" "0" euler_angle_convention = *xyz zyz } occupancies { randomize = False set = None } output { file_name = None } random_seed = None } fake_f_obs { k_sol = 0 b_sol = 0 b_cart = "0" "0" "0" "0" "0" "0" scale = 1 structure_factors_accuracy { algorithm = *fft direct cos_sin_table = False grid_resolution_factor = 0.3333333333 quality_factor = None u_base = None b_base = None wing_cutoff = None exp_table_one_over_step_size = None } mask { solvent_radius = 1.11 shrink_truncation_radius = 0.9 grid_step_factor = 4 verbose = 1 mean_shift_for_mask_update = 0.1 ignore_zero_occupancy_atoms = True } scattering_table = wk1995 it1992 *n_gaussian neutron } hydrogens { refine_sites = individual *riding refine_adp = one_b_per_residue *one_b_per_molecule individual refine_occupancies = one_q_per_residue *one_q_per_molecule individual contribute_to_f_calc = True xh_bond_distance_deviation_limit = 0 build { map_type = "mFobs-DFmodel" map_cutoff = 2 angular_step = 3 use_sigma_scaled_maps = True resolution_factor = 0.25 map_next_to_model { min_model_peak_dist = 0.7 max_model_peak_dist = 1.05 min_peak_peak_dist = 1 use_hydrogens = False } max_number_of_peaks = None peak_search { peak_search_level = 1 max_peaks = 0 interpolate = True min_distance_sym_equiv = None general_positions_only = False min_cross_distance = 1 } } } group_b_iso { number_of_macro_cycles = 3 max_number_of_iterations = 25 convergence_test = False run_finite_differences_test = False } adp { iso { max_number_of_iterations = 25 automatic_randomization_if_all_equal = True scaling { scale_max = 3 scale_min = 10 } } } tls { one_residue_one_group = None refine_T = True refine_L = True refine_S = True number_of_macro_cycles = 2 max_number_of_iterations = 25 start_tls_value = None run_finite_differences_test = False eps = 1e-06 } adp_restraints { iso { use_u_local_only = False sphere_radius = 5 distance_power = 1.69 average_power = 1.03 wilson_b_weight_auto = False wilson_b_weight = None plain_pairs_radius = 5 refine_ap_and_dp = False b_iso_max = None } } group_occupancy { number_of_macro_cycles = 3 max_number_of_iterations = 25 convergence_test = False run_finite_differences_test = False } group_anomalous { number_of_minimizer_cycles = 3 lbfgs_max_iterations = 20 number_of_finite_difference_tests = 0 } rigid_body { mode = *first_macro_cycle_only every_macro_cycle target = ls_wunit_k1 ml *auto target_auto_switch_resolution = 6 refine_rotation = True refine_translation = True max_iterations = 25 bulk_solvent_and_scale = True euler_angle_convention = *xyz zyz lbfgs_line_search_max_function_evaluations = 10 min_number_of_reflections = 100 multi_body_factor = 1 zone_exponent = 4 high_resolution = 3 max_low_high_res_limit = None number_of_zones = 5 } ncs { find_ncs { temp_dir = "" min_length = 10 njump = 1 njump_recursion = 10 min_length_recursion = 50 min_percent = 95 max_rmsd = 2 quick = True max_rmsd_user = 3 domain_finding_parameters { find_invariant_domains = True initial_rms = 0.5 match_radius = 2 similarity_threshold = 0.75 smooth_length = 0 min_contig_length = 3 min_fraction_domain = 0.2 max_rmsd_domain = 2 } verbose = False } find_automatically = True coordinate_sigma = None b_factor_weight = None excessive_distance_limit = None special_position_warnings_only = False restraint_group { reference = None selection = None coordinate_sigma = 0.05 b_factor_weight = 10 } restraint_group { reference = "chain A and (resseq 30:374 )" selection = "chain B and (resseq 30:374 )" coordinate_sigma = 0.05 b_factor_weight = 10 } } pdb_interpretation { apply_cif_modification { data_mod = None residue_selection = None } apply_cif_link { data_link = None residue_selection_1 = None residue_selection_2 = None } link_distance_cutoff = 3 disulfide_distance_cutoff = 3 chir_volume_esd = 0.2 peptide_link { cis_threshold = 45 discard_psi_phi = True omega_esd_override_value = None } nonbonded_distance_cutoff = None default_vdw_distance = 1 min_vdw_distance = 1 nonbonded_buffer = 1 vdw_1_4_factor = 0.8 translate_cns_dna_rna_residue_names = None clash_guard { nonbonded_distance_threshold = 0.5 max_number_of_distances_below_threshold = 100 max_fraction_of_distances_below_threshold = 0.1 } } geometry_restraints.edits { bond { action = *add delete change atom_selection_1 = None atom_selection_2 = None symmetry_operation = None distance_ideal = None sigma = None } angle { action = *add delete change atom_selection_1 = None atom_selection_2 = None atom_selection_3 = None angle_ideal = None sigma = None } } geometry_restraints.remove { angles = None dihedrals = None chiralities = None planarities = None } ordered_solvent { low_resolution = 2.4 mode = auto filter_only *every_macro_cycle output_residue_name = "HOH" output_chain_id = "W" output_atom_name = "O" b_iso_min = 1 b_iso_max = 80 anisotropy_min = 0.1 b_iso = None scattering_type = "O" occupancy_min = 0.1 occupancy_max = 1 occupancy = 1 primary_map_type = "mFobs-DFmodel" primary_map_cutoff = 3.2 secondary_map_type = "2mFobs-DFmodel" secondary_map_cutoff = 1.2 h_bond_min_mac = 1.2 h_bond_min_sol = 1.2 h_bond_max = 3.2 new_solvent = *isotropic anisotropic refine_adp = True refine_occupancies = False filter_at_start = True n_cycles = 3 ignore_final_filtering_step = False } peak_search { use_sigma_scaled_maps = True resolution_factor = 0.25 map_next_to_model { min_model_peak_dist = 1.8 max_model_peak_dist = 6 min_peak_peak_dist = 1.8 use_hydrogens = False } max_number_of_peaks = 5232 peak_search { peak_search_level = 1 max_peaks = 0 interpolate = True min_distance_sym_equiv = None general_positions_only = False min_cross_distance = 1.8 } } bulk_solvent_and_scale { bulk_solvent = True anisotropic_scaling = True k_sol_b_sol_grid_search = True minimization_k_sol_b_sol = True minimization_b_cart = False target = *ls_wunit_k1 ml symmetry_constraints_on_b_cart = True k_sol_max = 0.6 k_sol_min = 0 b_sol_max = 150 b_sol_min = 0 k_sol_grid_search_max = 0.6 k_sol_grid_search_min = 0 b_sol_grid_search_max = 80 b_sol_grid_search_min = 20 k_sol_step = 0.3 b_sol_step = 30 number_of_macro_cycles = 2 max_iterations = 25 min_iterations = 25 fix_k_sol = None fix_b_sol = None fix_b_cart { b11 = None b22 = None b33 = None b12 = None b13 = None b23 = None } apply_back_trace_of_b_cart = False verbose = -1 ignore_bulk_solvent_and_scale_failure = False } alpha_beta { free_reflections_per_bin = 140 number_of_macromolecule_atoms_absent = 225 n_atoms_included = 0 bf_atoms_absent = 15 final_error = 0 absent_atom_type = "O" method = *est calc estimation_algorithm = *analytical iterative verbose = -1 interpolation = False fix_scale_for_calc_option = None number_of_waters_absent = 613 sigmaa_estimator { kernel_width_free_reflections = 100 kernel_on_chebyshev_nodes = True number_of_sampling_points = 20 number_of_chebyshev_terms = 10 use_sampling_sum_weights = True } } mask { solvent_radius = 1.11 shrink_truncation_radius = 0.9 grid_step_factor = 4 verbose = -1 mean_shift_for_mask_update = 0.1 ignore_zero_occupancy_atoms = True } cartesian_dynamics { temperature = 300 number_of_steps = 200 time_step = 0.0005 initial_velocities_zero_fraction = 0 n_print = 100 verbose = -1 } simulated_annealing { start_temperature = 5000 final_temperature = 300 cool_rate = 100 number_of_steps = 25 time_step = 0.0005 initial_velocities_zero_fraction = 0 interleaved_minimization { number_of_iterations = 0 time_step_factor = 10 restraints = *bonds *angles } n_print = 100 update_grads_shift = 0.3 refine_sites = True refine_adp = False max_number_of_iterations = 25 mode = every_macro_cycle *second_and_before_last once first verbose = -1 } target_weights { wxc_scale = 0.5 wxu_scale = 1 wc = 1 wu = 1 fix_wxc = None fix_wxu = None optimize_wxc = False optimize_wxu = False shake_sites = True shake_adp = 10 regularize_ncycles = 50 verbose = 1 wnc_scale = 0.5 wnu_scale = 1 rmsd_cutoff_for_gradient_filtering = 3 } ias { b_iso_max = 100 occupancy_min = -1 occupancy_max = 1.5 ias_b_iso_max = 100 ias_b_iso_min = 0 ias_occupancy_min = 0.01 ias_occupancy_max = 3 initial_ias_occupancy = 1 build_ias_types = L R B BH use_map = True build_only = False file_prefix = None peak_search_map { map_type = *Fobs-Fmodel mFobs-DFmodel grid_step = 0.25 scaling = *volume sigma } } ls_target_names { target_name = *ls_wunit_k1 ls_wunit_k2 ls_wunit_kunit ls_wunit_k1_fixed \ ls_wunit_k1ask3_fixed ls_wexp_k1 ls_wexp_k2 ls_wexp_kunit \ ls_wff_k1 ls_wff_k2 ls_wff_kunit ls_wff_k1_fixed \ ls_wff_k1ask3_fixed lsm_kunit lsm_k1 lsm_k2 lsm_k1_fixed \ lsm_k1ask3_fixed } twinning { twin_law = None detwin { mode = algebraic proportional *auto map_types { twofofc = *two_m_dtfo_d_fc two_dtfo_fc fofc = *m_dtfo_d_fc gradient m_gradient aniso_correct = False } } } structure_factors_and_gradients_accuracy { algorithm = *fft direct cos_sin_table = False grid_resolution_factor = 0.3333333333 quality_factor = None u_base = None b_base = None wing_cutoff = None exp_table_one_over_step_size = None } r_free_flags { fraction = 0.1 max_free = 2000 lattice_symmetry_max_delta = 5 use_lattice_symmetry = True } }

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COURSE ANNOUNCEMENT - BIOCRYS 2008
by Daniele de Sanctis 15 May '08

15 May '08

On behalf of the organizers, Maria Armenia Carrondo and Thomas R. Schneider COURSE ANNOUNCEMENT - BIOCRYS 2008 Fundamentals of Modern Methods in Biocrystallography - 'What you always wanted to know about crystallography but never dared to ask' http://biocrys.itqb.unl.pt 4th - 11th October 2008 at the Instituto de Tecnologia Química e Biológica, Oeiras, Portugal. The topics of the second edition of this course will run from fundamentals such as symmetry, point groups and crystal systems, basic diffraction physics, reciprocal space and the Ewalds sphere, radiation damage, data processing, structure factors, Patterson function to modern methodologies including molecular replacement, SAD, MAD, MIR and maximum likelihood phasing, density modification, refinement, model building, twinning and structure validation. The course will be organized with lectures in the mornings and interactive practicals and tutorials in the afternoons. Evening lectures on current topics will be presented by the invited speakers. Instructors and speakers (confirmed): M. Archer, I. Bento, N. Berrow, G. Bunkoczi, M. Coll, K. Cowtan, Z. Dauter, D. de Sanctis, P. Donner, C. Frazão, E. Garman, C. Hermes, E. Hough, G. Leonhard, A. Leslie, P. Matias, A. Perrakis, T. Schneider, C. Vonrhein. 36 participants will be selected with preference to scientists at the beginning of their crystallographic career and to those from Europe. Registration fee is 500 Eur and a fee of 700 Eur is requested for full board and accommodation. Selected applicants will have to pay the registration fee by bank transfer before arrival. A very limited number of grants may be available to partially cover the registration fees and will be paid upon students arrival. For application, please please fill the form on the web page http://www.embl-hamburg.de/workshops/2008/BIOCRYST08/ by the 15th of July For more information visit the course web page http://biocrys.itqb.unl.pt -- Daniele de Sanctis, PhD Homo sum humani nil alienum a me puto ______________________________________________________________ phone ++ 351 21 4469 662 fax ++ 351 21 4433 664 e-mail de.sanctisd(a)gmail.com, sanctis(a)itqb.unl.pt Mailing address: ITQB, Av. República, Apartado 127 2781-901 Oeiras Portugal

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User proposal submission for Collaborative Crystallography at BCSB
by Banumathi Sankaran 14 May '08

14 May '08

Dear Users, The Berkeley Center for Structural Biology (BCSB) is pleased to announce the launch of a Collaborative Crystallography Pilot Program (CC) at the Advanced Light Source in Berkeley. Through this program, scientists will be able to send protein crystals to BCSB staff researchers for data collection and analysis. The CC Pilot Program can provide an number of benefits to researchers: * Obtain high quality data and analysis through collaborating with expert beamline researchers; * Rapid turn around on projects; * 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 egular ALS General User proposal review process for beamtime allocation. Proposals will be reviewed and ranked by the Proposal Study Panel, and beamtime will be allocated accordingly. BCSB staff will schedule the 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://alsusweb.lbl.gov/4DCGI/WEB_GetForm/PXProposalEntry.shtml/Initialize 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 July/August, 2008, proposals must be submitted by May 15, 2008. The deadline for CC proposals for the time period September/October 2008 is July 15, 2008. Regards, Banumathi Sankaran

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Fixing waters around metal atom
by Jendrek 14 May '08

14 May '08

Hi, I have a structure with a metal beautifully coordinated by 3 water molecules. However, every time I run phenix.refine water picking they get removed (probably due to combination of being too close to metal/too deep in the density). So far I've been manually reentering them into pdb but it becomes a bit frustrating. Is there a way to fix those waters during water picking? Regards, Andrzej -- Andrzej LYSKOWSKI, Ph.D. (andrzej[.]lyskowski[(a)]helsinki[.]fi) Institute of Biotechnology - Structural Biology & Biophysics P. O. Box 65, Viikinkaari 1 FIN-00014 University of HELSINKI, FINLAND TEL.: 358 9 191 58955 FAX : 358 9 191 59940

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Beamtime available; Deadline for applications : May 15.
by Peter Zwart 13 May '08

13 May '08

Dear All, The Berkeley Center for Structural Biology (BCSB) has recently completed a major upgrade of the Sector 5.0 beamline optics. A five- to tenfold improvement in available flux has been achieved at the side-station beamlines (5.0.1 and 5.0.3), which now generate 1.5x10^11 photons per second at 0.97 Angstrom. This wavelength is slightly above the Se K edge making them ideal for performing Se SAD experiments. The performance of 5.0.2 (a tunable beamline) has improved by a factor of 3 to 4. It now generates a peak flux of 8x10^11 photons per second under typical user operations. The upgrade has also extended the energy range of 5.0.2 to 16 keV, enabling the routine use of shorter wavelengths and anomalously scattering elements such as bromine. All the BCSB beamlines have robotic sample changers. The sector 5 beamlines are equiped with Berkeley Automounters (BAMs). The tuneable beamlines 8.2.1 and 8.2.2 are now equiped with Actor sample changers. Please visit http://bcsb.lbl.gov/ for more details about the Center and its beamlines. If you'd like to take advantage of the upgrades to these BCSB beamlines, submit a General User proposal by May 15, 2008 in order to be considered for the July-August schedules at the Advanced Light Source. 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-mailing 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.) Regards Peter Zwart -- ----------------------------------------------------------------- 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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B factor
by Jianghai Zhu 11 May '08

11 May '08

Hi, When TLS is used, phenix.refine gives 6 ANISOU B factors for each atoms. But we also get a number at the normal isotropic B factor position. If that number is the isotropic B factor, how was it calculated? Did you use something like the following? Uiso(e)^2=U11*e1^2+U22*e2^2+U33*e3^2+2U12*e1e2+2U13*e1e3+2U23*e2e3 Is it the same as the output from tslanl if using refmac5? -- Jianghai

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GRC on Diffraction Methods in Structural Biology
by Andrew Leslie 09 May '08

09 May '08

There is still time to apply to attend this GRC, relevant to researchers interested in Methods Development - details below! The official closing date is 22nd June, but places are limited to a total of 125. Best wishes Elspeth Garman and Andrew Leslie Gordon Research Conference on Diffraction Methods in Structural Biology July 13-18, 2008, Bates College, Lewiston, Maine, USA Co-Chairs: Elspeth Garman & Andrew Leslie The 2008 Gordon Research Conference on Diffraction Methods in Structural Biology will encompass advances in the methodology for macromolecular X-ray crystallography, and other diffraction/scattering applications. The full confirmed programme and timetable for the meeting can now be found below and at: http://www.grc.org/programs.aspx?year=2008&program=diffrac as well as details on how to register (registration closes on 22nd June 2008 but attendance is limited to 125 researchers). All macromolecular crystallographers interested in Methods development are encouraged to apply. To promote a lively meeting, we hope that all participants will present a poster and contribute to the discussions. *Confirmed Program as at 8th May 2008.* *MACROMOLECULAR STRUCTURES: PUSHING THE BOUNDARIES * Discussion Leader: *Janet Smith* (University of Michigan at Ann Arbor, USA) *Jens Preben Morth* (Aarhus University, Denmark) "Structure determination of the sodium-potassium pump" *Jack Johnson* (Scripps Research Institute, USA) "Crystallography of Viral Maturation Intermediates: Large Unit Cells, Particle Dynamics, and Energy Landscapes" *EXPERIMENTAL ASPECTS* Discussion Leader: *James Holton* (University of California, Berkeley, USA) *Douglas Juers* (Whitman College, USA) "Rational approaches to cryo-crystallography protocols" *Zbyszek Dauter* (Frederick Cancer Institute, USA) "A thoughtful approach to data collection" *Eddie Snell* (Hauptman-Woodward Medical Research Institute, USA) "Are X-rays damaging to structural biology? A case study with xylose isomerase" *Martin Weik* (Institut de Biologie Structurale, Grenoble, France) "Temperature-controlled cryo-crystallography to study the structural dynamics of proteins" *COMPLEMENTARY TECHNIQUES* Discussion Leader: *Peter Kuhn* (Scripps Research Institute, USA) *Junko Yano* (Lawrence Berkeley National Laboratory, USA) "Combination of XAS and XRD for studying a high-resolution structure of the photosynthetic water-splitting catalyst" *Dean Myles* (Oak Ridge National Laboratory USA) "New opportunities for neutron structural biology" *Carrie Wilmot* (University of Minnesota, USA) "Single crystal spectroscopy coupled to crystallography" *FUTURE DIRECTIONS IN SYNCHROTRON BASED MACROMOLECULAR CRYSTALLOGRAPHY * Discussion Leader: *Elizabeth Duke* (Diamond Light Source, UK) *Soichi Wakatsuki* (KEK, Japan) "Microfocus and low energy PX developments looking towards next generation synchrotron sources" *Ed Mitchell* (ESRF, Grenoble, France) "Bigger, better, faster, more: The ESRF Upgrade Programme" *Aina Cohen* (SSRL, USA) "Automation, Robotics and Remote Access at the SSRL Protein Crystallography Beam Lines" *Frank von Delft* (Structural Genomics Consortium, Oxford, UK) "A User's Wish: An Experiment-Focussed Beamline Interface" *EMERGING TECHNOLOGIES* Discussion Leader: *Andrew Leslie* (MRC-LMB, Cambridge, UK) *Robert F. Fischetti* (GM/CA-CAT, Argonne National Laboratory, USA) "Where have all the photoelectrons gone?" *Clemens Schulze-Briese* (Swiss Light Source, Villigen, Switzerland) "PILATUS 6M - the first year of regular user operation" *COMPUTATIONAL METHODS* Discussion Leader: *Airlie McCoy* (University of Cambridge, UK) *Sasha Popov* (ESRF, Grenoble, France) "BEST SAD data collection" *Paul Adams* (Lawrence Berkeley Laboratory, USA) "Automated structure solution with PHENIX" *Kevin Cowtan* (University of York, UK) "The 3 R's of automated model building: R-factors, resolution, and refinement" *George Phillips* (University of Wisconsin-Madison, USA) "Interpretation of electron density maps from protein crystals" *CHALLENGING PROBLEMS / MEMBRANE PROTEINS * Discussion Leader: *Tom Terwilliger* (Los Alamos National Laboratory, USA) *Chris Tate* (LMB-MRC Cambridge, UK) "Thermostabilisation and structure determination of a beta1 adrenergic receptor" *Mike Lawrence* (The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia) "Pursuit of the structure of the human insulin receptor ectodomain" *Mark Mayer* (NIH, Bethesda, USA) "Structure and function of allosteric ion binding sites in glutamate receptor ligand binding domains" *TALKS SELCETCED FROM POSTERS* *VALIDATION* Discussion Leader: *Ana Gonzales* (Stanford Synchrotron Radiation Laboratory, USA) *Gerard Kleywegt* (University of Uppsala, Sweden) "Validation" *Jane Richardson* (Duke University, USA) "MolProbity Progress: RNA, Auto-corrections, and H redux" *IMAGING METHODS OF THE FUTURE* Discussion Leader: *Raimond Ravelli* (Leiden University Medical Centre, The Netherlands) *Steve Ludtke* (Baylor College of Medicine, Houston, USA) "Resolution and Molecular Motion, Frontiers in CryoEM" *Carolyn Larabell* (Lawrence Berkeley National Laboratory) TBA

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Re: [phenixbb] mtz test set
by Ralf W. Grosse-Kunstleve 02 May '08

02 May '08

Hi Mark, > yes. however arp/warp has lost this ability in the ccp4i "classic" > mode. Oh, too bad. I wrote a small mtz_free_flipper.py script that will be part of the next CCI Apps maintenance release (hopefully tomorrow). If you want to use it right now, get the current cctbx bundle from here: http://cci.lbl.gov/cctbx_build/all.html Build tag: 2008_05_02_0119 (or later) Pick a bundle from the "cctbx+Python" column. You can install it anywhere, e.g. in /var/tmp/junk. After the perl cctbx*.selfx command is finished (a few seconds), source the setpaths script for your shell as usual, then run this command: cctbx.python cctbx_sources/iotbx/iotbx/examples/mtz_free_flipper.py your.mtz It will write a file free_flipped_your.mtz. The script assumes the R-free flags column label is "R-free-flags". If your label is different, copy the example script, modify the label (should be obvious) and run the modified script: cctbx.python copy_of_mtz_free_flipper.py your.mtz Note: the script will not work with the current CCI Apps because I had to add something to the mtz module last night to keep the script simple. Ralf

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model bias: phaser + prime-and-switch VS simulated annealing in phenix VS simulated annealing in cns + prime and switch
by hari jayaram 02 May '08

02 May '08

First off sorry for the cross post across bbs I have a molecular replacement solution for a single site mutant for data that goes out to 2.8 A. After molecular replacement in phaser I run the following and examine the maps for bias from the model. Option1: simluated annealing refinement in phenix using the phaser mtz Option2: take the phaser mtz and then just run prime and switch in resolve and look at the map Option3: First part: take the phaser mtz and then run simulated annealing and sigmaa in cns 1.2.2 . Second part: Run prime-and-switch using part1s model phases and modified Fs I am observing that Option 1 and Option 2 the maps are indistinguishable from each other and show very little bias from the model. In Option 3 just cns simulated annealing does not go as far at removing bias as cns simulated annealing plus prime-and-switch. Although my estimate of model bias is just a "look and see" feeling. Since I lack a thorough understanding of the relative merits of these algorithms I have the following questions 1)Does simulated annealing refinement as implemented in phenix use a prime-and-switch style approach to modify phases at any point to guide the refinement 2) Am I wrong in assuming that just simulated annealing and sigma-aa weighted maps for cns (Option 3 part 1) are not as good as cns simulated annealing + sigmaa+ prime_and_switch ( option3 part 2) Hoping to get a better idea on how well these approaches fair at removing model bias Hari Jayaram Postdoc , Brandeis University

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pseudo-translational symmetry refinement
by a a 02 May '08

02 May '08

Dear all: We have a set of crystal data having psuedo-translational symmetry when examined with xtriage: ------------------------------------------------------------------------------- Twinning and intensity statistics summary (acentric data): Statistics independent of twin laws - <I^2>/<I>^2 : 2.519 - <F>^2/<F^2> : 0.724 - <|E^2-1|> : 0.854 - <|L|>, <L^2>: 0.504, 0.337 Multivariate Z score L-test: 1.854 The multivariate Z score is a quality measure of the given spread in intensities. Good to reasonable data are expected to have a Z score lower than 3.5. Large values can indicate twinning, but small values do not necessarily exclude it. No (pseudo)merohedral twin laws were found. Patterson analyses - Largest peak height : 67.742 (corresponding p value : 4.897e-06) The analyses of the Patterson function reveals a significant off-origin peak that is 67.74 % of the origin peak, indicating pseudo translational symmetry. The chance of finding a peak of this or larger height by random in a structure without pseudo translational symmetry is equal to the 4.8972e-06. The detected tranlational NCS is most likely also responsible for the elevated intensity ratio. See the relevant section of the logfile for more details. The results of the L-test indicate that the intensity statistics behave as expected. No twinning is suspected. ------------------------------------------------------------------------------- The structure was solved by auto-sad at 2.7A. However, the r-factor can not be lowered by phenix.refine (TLS+ADP+rigid). Is there any manipuliations we can do to deal with this situation? Thanks, Zhiyong Ren, MD Anderson Cancer Center ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

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