May 2013 - phenixbb - phenix-online.org

labelit distl_minimum_number_spots_for_indexing
by Christian Roth 22 Sep '15

22 Sep '15

Dear Phenix-Team I installed the latest nightly build 1.8-1069. I tried to index some diffraction images and to overwrite the minimum usable spots for indesing I tried the suggested command. However If I try this command, it seems that it does not exist. At least in the list of the possible distl commands it does not show up. Do I have to install some additional stuff or change some preferences to get this command? Best Regards Christian

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Phenix version 1.8.2 released
by Paul Adams 26 Jun '13

26 Jun '13

The Phenix developers are pleased to announce that version 1.8.2 of Phenix is now available. Binary installers for Linux, Mac OSX, and Windows platforms are available at the download site: http://phenix-online.org/download/ Highlights from this version: Ensemble refinement, updated hydrogen parameters in refinement and validation, mmCIF reading and writing, LLG maps output from refinement, ligand pipeline for automated solution of protein/ligand complexes, autobuilding starting from a very accurate but very small part of a model, CC* calculation from unmerged data, maximum entropy maps, and PDB editor. Graphical interface: ==================== - New GUIs: phenix.merging_statistics, phenix.pdb_editor General: ======== - Multiple bug fixes - phenix.refine, phenix.reduce, and MolProbity updated to use consistent, revised, electron-cloud centers for hydrogen positions as default (for X-ray) - also see MolProbity website for details: http://molprobity.biochem.duke.edu - mmCIF format now supported in place of PDB format for input to many programs - new commands: phenix.ensemble_refinement, phenix.ligand_pipeline, phenix.sort_hetatms, phenix.cc_star, phenix.pdb_editor, phenix.maximum_entropy_map Refinement: =========== - phenix.refine - support for LLG map type - uses Phaser to compute residual anomalous LLG map - best when used with group_anomalous strategy, which will flatten the LLG map around existing anomalous scatterers with refined f'/f''. - alternatively, anomalous_residual map type (similar but less sensitive) - automatic linking in refinement and pdbtools for residues in the same chain - enabled with automatic_linking.intra_chain=True; this includes carbohydrate linking to protein and between sugars, and covalently bound ligands. - optional output of mmCIF format model and data files - phenix.ensemble_refinement (new command): - New method for refining ensemble models - Combines MD simulation with X-ray restraints that simultaneously account for anisotopic and anharmonic atomic distributions. - For full description see: Burnley BT, Afonine PV, Adams PD, Gros P. 2012. Modelling dynamics in protein crystal structures by ensemble refinement. eLife 1:e00311. doi: 10.7554/elife.00311. Experimental Phasing and Model Building: ======================================== - phenix.autobuild: - now uses torsion NCS parameterization when NCS is used in refinement - building starting from a very accurate but very small part of a model: You can now use the keyword rebuild_from_fragments=True to start rebuilding from fragments of a model. You might want to use this if you look for ideal helices using Phaser, then rebuild the resulting partial model, as in the Arcimboldo procedure. The special feature of finding helices is that they can be very accurately placed in some cases. This really helps the subsequent rebuilding. If you have enough computer time, then run it several or even many times with different values of i_ran_seed. Each time you'll get a slightly different result. - Base-pairing in RNA building -- phenix.autobuild will now try to guess which bases in a model are base-paired, and if there is no positive sequence match to the model, the bases that are base-paired will be chosen to be complementary. You can set the cutoff for base pairing with the keyword dist_cut_base. - waters are automatically named with the chain of the closest macromolecule if you set sort_hetatms=True. This is for the final model only. - you can supply a target position for your model with map_to_object=my_target.pdb. Then at the very end of the run your molecule will be placed as close to this as possible. The center of mass of the autobuild model will be superimposed on the center of mass of my_target.pdb using space group symmetry, taking any match closer than 15 A within 3 unit cells of the original position. The new file will be overall_best_mapped.pdb. Molecular Replacement: ====================== - phenix.mr_rosetta - You can now give commands for Rosetta in mr_rosetta, including a command to specify where disulfide bonds are located - The Rosetta models are now identified by an ID number so that they have unique names - Default number of homology models to download is now 1 (was 5) - Default number of NCS copies (if ncs_copies=Auto) is number leading to solvent content closest to 50%; if ncs_copies=None then all plausible values of ncs_copies are tested. New commands: ============= - phenix.ligand_pipeline (new command): - combines Xtriage, Phaser, eLBOW, phenix.refine, AutoBuild, and LigandFit to automatically solve protein/ligand complexes - optional integration with Coot (parameter interactive=True) allows semi-interactive operation where more rebuilding is required - phenix.cc_star (new command): - combined assessment of model and data quality, as outlined in Karplus & Diederichs (2012) Science 336:1030-3. - summary also output by phenix.model_vs_data if additional unmerged_data keyword is specified - phenix.maximum_entropy_map (new command): - tool to compute maximum entropy map from map coefficients. The program reads input Fourier map coefficients and modifies corresponding synthesis using Maximum-Entropy Method (MEM). The MEM modified map is everywhere positive, smooth and is of higher resolution. The method uses is a modification of Gull & Daniell (1978) algorithm. - phenix.sort_hetatms (new command): - rearranges heteroatoms (ligands, waters, etc.) in a model so they are paired with the nearest macromolecule chain, similar to the PDB's processing of models - phenix.pdb_editor (new command): - graphical editor for PDB files, based on tree view of model hierarchy - perform common operations such as chain renaming, renumbering, manipulation of atomic properties, add/remove atoms Ligands: ======== - phenix.ready_set: - methyl rotations now automatic when adding explicit hydrogens (also in phenix.reduce) - more options adding deuteriums to a model have been introduced Miscellaneous: ============== - phenix.xtriage: - include merging statistics if unmerged intensities are used as input - phenix.maps: - added wavelength parameter and support for anomalous residual and Phaser LLG map coefficients For a full list of changes see: http://www.phenix-online.org/documentation/CHANGES Please note that this publication should be used to cite use of Phenix: PHENIX: a comprehensive Python-based system for macromolecular structure solution. P. D. Adams, P. V. Afonine, G. Bunkóczi, V. B. Chen, I. W. Davis, N. Echols, J. J. Headd, L.-W. Hung, G. J. Kapral, R. W. Grosse-Kunstleve, A. J. McCoy, N. W. Moriarty, R. Oeffner, R. J. Read, D. C. Richardson, J. S. Richardson, T. C. Terwilliger and P. H. Zwart. Acta Cryst. D66, 213-221 (2010). Full documentation is available here: http://www.phenix-online.org/documentation/ There is a Phenix bulletin board: http://www.phenix-online.org/mailman/listinfo/phenixbb/ Please consult the installer README file or online documentation for installation instructions. Direct questions and problem reports to the bulletin board or: help(a)phenix-online.org and bugs(a)phenix-online.org Commercial users interested in obtaining access to Phenix should visit the Phenix website for information about the Phenix Industrial Consortium. The development of Phenix is principally funded by the National Institute of General Medical Sciences (NIH) under grant P01-GM063210. We also acknowledge the generous support of the members of the Phenix Industrial Consortium. -- Paul Adams Deputy Division Director, Physical Biosciences Division, Lawrence Berkeley Lab Division Deputy for Biosciences, Advanced Light Source, Lawrence Berkeley Lab Adjunct Professor, Department of Bioengineering, U.C. Berkeley Vice President for Technology, the Joint BioEnergy Institute Laboratory Research Manager, ENIGMA Science Focus Area 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: Louise Benvenue [ LBenvenue(a)lbl.gov ][ 1-510-495-2506 ] --

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Discrepancy between R-factors from phenix.refine vs phenix Generate "Table 1"
by Sam Stampfer 12 Jun '13

12 Jun '13

Dear Phenix Community, I am preparing my structure for deposition and ran it through the Generate "Table 1" function in phenix. The inputs I gave it were my .mtz structure factors file, the final pdb coordinate file, and the log file from hkl2000. I did not provide unmerged data. My pdb file (which had been refined using phenix.refine) had values of r_work=0.2342 r_free=0.2603 However, phenix.model_vs_data (from Generate "Table 1") gave me r_work=0.2940 r_free=0.3150 I also got this warning about resolution limits, but I think it should not have affected the R-free calculation to this extent: WARNING: Resolution limits in scaling log for structure A549T are inconsistent with resolution limits in the MTZ file: 50.00 - 3.02 (in logfile) 48.47 - 3.03 (in MTZ file) When I refined my model in phenix, I used the twin law h,-h-k,-l. I read in the documentation that twinning can account for some of this discrepancy, but that the program is supposed to take twinning into account if it will lower the calculated R-work by more than 2%, which it doesn't seem to have done (or there is some other problem with my data). Thanks for your help! -Sam

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Re: [phenixbb] Discrepancy between R-factors from phenix.refine vs phenix Generate "Table 1"
by Michael Thompson 01 Jun '13

01 Jun '13

As another follow up to this point, I have had a recent example where Xtriage reported that my intensity statistics indicated twinning (<|L|>=0.399 and <L^2>=0.227, alpha=0.4). After having refined the structure with the suggested twin law, and making composite omit maps along the way (using autobuild with no twin law), I ran model vs. data at the end of refinement and noticed that it reported R/Rfree that were about 10% higher than the R/Rfree from refinement, similar to what the original post described. I checked the model vs. data logfile and found that the L-test routine used by model vs. data was failing, so the subsequent analysis was carried out as if there was no twinning. So in my case, the crystal was twinned, but model vs. data was not able to perform the L-test so it was outputting incorrect R-factors. The error message at the top of the model vs. data log file is: Twin analysis failed: Python argument types in l_test.__init__(l_test, miller_index, double, space_group, bool, float, float, float, int) did not match C++ signature: __init__(_object*, scitbx::af::const_ref<cctbx::miller::index<int>, scitbx::af::trivial_accessor> miller_indices, scitbx::af::const_ref<double, scitbx::af::trivial_accessor> intensity, cctbx::sgtbx::space_group space_group, bool anomalous_flag, long parity_h, long parity_k, long parity_l, unsigned long max_delta_h) Twin analysis failed: Python argument types in l_test.__init__(l_test, miller_index, double, space_group, bool, float, float, float, int) did not match C++ signature: __init__(_object*, scitbx::af::const_ref<cctbx::miller::index<int>, scitbx::af::trivial_accessor> miller_indices, scitbx::af::const_ref<double, scitbx::af::trivial_accessor> intensity, cctbx::sgtbx::space_group space_group, bool anomalous_flag, long parity_h, long parity_k, long parity_l, unsigned long max_delta_h) Perhaps there are some other users who are seeing this behavior because the L-test fails within model vs. data. Mike ----- Original Message ----- From: "Nathaniel Echols" <nechols(a)lbl.gov> To: "PHENIX user mailing list" <phenixbb(a)phenix-online.org> Sent: Wednesday, May 29, 2013 5:18:57 PM GMT -08:00 US/Canada Pacific Subject: Re: [phenixbb] Discrepancy between R-factors from phenix.refine vs phenix Generate "Table 1" On Wed, May 29, 2013 at 4:13 PM, Sam Stampfer <Samuel.Stampfer(a)tufts.edu> wrote: > When I refined my model in phenix, I used the twin law h,-h-k,-l. I read in > the documentation that twinning can account for some of this discrepancy, > but that the program is supposed to take twinning into account if it will > lower the calculated R-work by more than 2%, which it doesn't seem to have > done (or there is some other problem with my data). Okay, the problem is that your data don't actually appear to be twinned. The automatic method used by phenix.model_vs_data (which is used internally for Table 1 and the validation GUI) only tries possible twin laws if the results of the "L test" show a suspicious distribution of intensities. Your data look fine, so it doesn't bother trying the twin laws. That the R-factors are lower when you refine with a twin law isn't necessarily indicative of the data actually being twinned - Garib Murshudov has looked into this in detail but I confess to being ignorant of the math (but I can probably dig up his paper on the subject if anyone is interested). However, I'm pretty sure the data are actually in a higher-symmetry space group. Will send details and new files off-list (probably tomorrow at this rate). I should probably change some of the programs and/or documentation to make it more clear what is being done internally, since it took me a bit of digging to realize what was going on. In general, though, always be very careful before running twinned refinement! I have seen several users do this by mistake when they really had higher symmetry. The maps will also be more model-biased when using twinned refinement, so it's good to avoid doing this unless absolutely necessary. -Nat _______________________________________________ phenixbb mailing list phenixbb(a)phenix-online.org http://phenix-online.org/mailman/listinfo/phenixbb -- Michael C. Thompson Graduate Student Biochemistry & Molecular Biology Division Department of Chemistry & Biochemistry University of California, Los Angeles miket(a)chem.ucla.edu

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Re: [phenixbb] refinement of partly occupied water molecules?
by krimmer＠staff.uni-marburg.de 31 May '13

31 May '13

Dear Nathaniel, dear Pavel, thank you for your fast answers! > currently phenix.refine can add automatically only fully occupied > waters (I am not sure it will ever use atomic model for partially > occupied waters). If necessary, add partially occupied waters > yourself manually. Make sure they have properly set altlocs > (alternative location identifiers): non blank (say A and B). Is it current praxis to let phenix.refine freely refine the occupancy of water molecules (adding partially occupied water molecules in coot and don’t fix the occupancy in phenix)? If I do so, these water molecules are refined by phenix.refine with occupancies between 0.4-0.8. My resolution range was 1.1 – 1.4 Å. > The nightly builds have an option in phenix.refine to place ions > automatically based on a variety of criteria (still being tuned). > However, what you describe doesn't sound like any ion coordination > motif that I've read about. Could you please send us a picture that > shows the density in context? Some of the other readers with more > experience in "blobology" may recognize it. [if our list server > complains about the size of the message, just ignore it, I'll approve > it for posting] Attached you will find the image of the blob. I think it’s easily visible that the density blob is in the middle of the five-ring and that there is also a (smaller) blob in the middle of the six-ring. The water which occupies the blob was not yet refined with phenix, I just put it there to measure the distances to the carbon atoms. Best regards, Stefan

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gap between Wilson B and average B
by fn1＠rice.edu 30 May '13

30 May '13

Dear all, I have a structure at about 3.5 A, which has a wilson B of about 109 and has an average B factor from model is only 49 (I did not use TLS). I read from the previous posts that wilson B is sometimes smaller than average B, but in my case it is reversed. I look at the distribution of model B factors, they are in the range of 8 to 132. Is there any problem with the refinement of this structure? Thanks in advance for all advice! Regards, Fengyun

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refinement of partly occupied water molecules?
by krimmer＠staff.uni-marburg.de 30 May '13

30 May '13

Dear all, I have a question concerning the refinement of partly occupied water molecules: in some of my macromolecular crystal structures with resolutions between 1.1 - 1.4 Å, mainly in the second solvation shell round positive Fo-Fc electron density blobs are detectable which show after assignment of a water molecule to these blob and subsequent refinement with Phenix refine a good-looking calculated 2Fo-Fc electron density (round shape, the 2Fo-Fc map appears at a contour level of σ = 1.0 - 1.4), but there also occurs a small negative Fo-Fc electron density detectable inside the 2Fo-Fc density blob. The negative Fo-Fc electron density disappears if the occupancy of the water molecule is refined by Phenix or manually set lower than 100% occupancy. Therefore, I think these positions are partly occupied by water molecules, but I am not sure how I should handle it/how it is generally handled. I would be thankful for any advice and/or literature about this topic. My second question is concerning a density blob in perfect coordination distance to an indolyl group (perfectly located in the middle of the five-ring, with 3.4 Å distance to every of the five carbon atoms of the five-ring). What‘s the best way to find out which ion possibly occupies this position? I tried Na+ and Ca2+, but after refinement big negative Fo-Fc blobs appear in both cases (maybe the ion at this position is only partly occupied?). There is no anomalous signal detectable at this position (data collection wavelength was 0.91841 nm). After the refinement of a water molecule at this position, a positive Fo-Fc election density is still there. Thank you for your help! Stefan

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R-merge
by Mengbin Chen 30 May '13

30 May '13

Dear Phenix Users, I have R-merge values equal 0.000 from highest resolution shell (which corresponds to values larger than 1.000) in a data set processed by HKL2000, with redundancies higher than 10 (I know this may help in increasing R-merge). I am not sure if this is going to be a problem of Table 1 for the reviewers. Could you kindly drop me your suggestions? Thank you in advance, Mengbin Chen -- Mengbin Chen Department of Chemistry University of Pennsylvania

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phenix.refine using anomalous concepts for neutron data?
by Derek Logan 29 May '13

29 May '13

Hi, I'm doing a joint X-ray neutron refinement in Phenix and have run into some behaviour that puzzles me. I had not been paying any attention to the use or non-use of anomalous signal in the neutron dataset, as This is what I get if I let phenix.refine itself decide whether or not to use anomalous data: ================================= Neutron data ================================ F-obs: neutron.mtz:FO,SIGFO,DANO,SIGDANO,ISYM Miller array info: neutron.mtz:FO,SIGFO,DANO,SIGDANO,ISYM Observation type: xray.reconstructed_amplitude Type of data: double, size=16672 Type of sigmas: double, size=16672 Number of Miller indices: 16672 Anomalous flag: True Unit cell: (removed) Space group: P 21 21 21 (No. 19) Systematic absences: 0 Centric reflections: 1258 Resolution range: 29.22 1.89826 Completeness in resolution range: 0.785008 Completeness with d_max=infinity: 0.78486 Bijvoet pairs: 6832 Lone Bijvoet mates: 1750 Anomalous signal: 0.0876 Number of F-obs in resolution range: 16672 Number of F-obs<0 (these reflections will be rejected): 0 Number of F-obs=0 (these reflections will be used in refinement): 0 Refinement resolution range: d_max = 29.2200 d_min = 1.8983 and this is what I get if I forcibly switch off use of anomalous data in the phenix.refine GUI: ================================= Neutron data ================================ F-obs: neutron.mtz:FO,SIGFO,DANO,SIGDANO,ISYM Miller array info: neutron.mtz:FO,SIGFO,DANO,SIGDANO,ISYM Observation type: xray.reconstructed_amplitude Type of data: double, size=16672 Type of sigmas: double, size=16672 Number of Miller indices: 16672 Anomalous flag: True Unit cell: (removed) Space group: P 21 21 21 (No. 19) Systematic absences: 0 Centric reflections: 1258 Resolution range: 29.22 1.89826 Completeness in resolution range: 0.785008 Completeness with d_max=infinity: 0.78486 Bijvoet pairs: 6832 Lone Bijvoet mates: 1750 Anomalous signal: 0.0876 force_anomalous_flag_to_be_equal_to=False Reducing data to non-anomalous array. R-linear = sum(abs(data - mean(data))) / sum(abs(data)) R-square = sum((data - mean(data))**2) / sum(data**2) In these sums single measurements are excluded. Redundancy Mean Mean Min Max Mean R-linear R-square unused: - 29.2234 bin 1: 29.2234 - 4.0863 1 2 1.699 0.0240 0.0011 bin 2: 4.0863 - 3.2448 1 2 1.793 0.0302 0.0022 bin 3: 3.2448 - 2.8350 1 2 1.800 0.0417 0.0041 bin 4: 2.8350 - 2.5760 1 2 1.764 0.0486 0.0054 bin 5: 2.5760 - 2.3914 1 2 1.745 0.0505 0.0051 bin 6: 2.3914 - 2.2505 1 2 1.717 0.0513 0.0051 bin 7: 2.2505 - 2.1378 1 2 1.658 0.0533 0.0056 bin 8: 2.1378 - 2.0448 1 2 1.614 0.0611 0.0074 bin 9: 2.0448 - 1.9661 1 2 1.575 0.0634 0.0075 bin 10: 1.9661 - 1.8983 1 2 1.485 0.0736 0.0097 unused: 1.8983 - Fobs statistics after all cutoffs applied: Miller array info: None Observation type: xray.amplitude Type of data: double, size=9840 Type of sigmas: double, size=9840 Number of Miller indices: 9840 Anomalous flag: False Unit cell: (removed) Space group: P 21 21 21 (No. 19) Systematic absences: 0 Centric reflections: 1258 Resolution range: 29.22 1.89826 Completeness in resolution range: 0.855801 Completeness with d_max=infinity: 0.855503 What's going on here? If I let phenix.refine decide automatically, it looks like it's reading in F+ and F- separately and regarding them as independent in the refinement. If I force "no anomalous" it merges them. However I can't work out whether in either case it has actually read FOBS instead of the Friedel mates. According to the SCALA manual the I+ and I- columns will always be written out even if the keyword ANOMALOUS OFF is used, so this is a potential pitfall for many. In addition, phenix.refine seems to identify the neutron data first as xray.reconstructed_amplitude then as xray.amplitude even though the data are explicitly defined as neutron data in the GUI. I can send more information if required! Thanks Derek ________________________________________________________________________ Derek Logan tel: +46 46 222 1443 Associate Professor mob: +46 76 8585 707 Dept. of Biochemistry and Structural Biology www.cmps.lu.se<http://www.cmps.lu.se> Centre for Molecular Protein Science www.maxlab.lu.se/node/307<http://www.maxlab.lu.se/node/307> Lund University, Box 124, 221 00 Lund, Sweden www.saromics.com<http://www.saromics.com>

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Structure Comparison questions
by Heather Condurso 29 May '13

29 May '13

Dear all, I have a few related structures that I would like to compare to make figures for publication but I have a few issues. The biggest issue is that my structures are large (12- 422aa chains) and any attempt at simple alignment in pymol results in a crash. I would like to first compare entire structures, but also compare the differences between related chains in the same structure. I want to look at the small differences in the active site density. What is the best way to do this? Is there a simple way to do this or do I need to make separate pdb files for each chain? Can I use the same mtz or should I rename copies? I will try a few things but any advice would be greatly appreciated. Heather condurso(a)bc.edu

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