February 2016 - phenixbb - phenix-online.org

Refine pixel size of map (for EM data)?
by Oliver Clarke 26 Jul '16

26 Jul '16

Hello, I wonder whether it would be possible to add an option for phenix.real_space_refine to allow refinement of the pixel size of the map (or the unit cell dimensions - just an overall size scale factor), and write out the altered map at the end of refinement. Although we try to calibrate this as best as we are able at the time of data collection, it is never perfect - for example, in one case I have dealt with, our nominal pixel size out of the scope is 1.19 Å, but the pixel size calibrated based on a crystal structure of a fragment of the protein is 1.25 Å. This is not a huge difference, but it is sufficient I think to have a substantial impact on refinement, particularly as regards clash assessment and H-bond/sec struc restraints. In cases where one does not have a solved crystal structure to use for calibration, perhaps refining the pixel size in conjunction with the geometry might be of some use? Cheers, Oli

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Feature request: multi-stage refinement protocols from the GUI?
by Tristan Croll 11 Mar '16

11 Mar '16

Hi all, I'm personally a big fan of the Phenix GUI, in particular for its automated record keeping for different runs. One thing I really wish it had, though, is the option to define more complex refinement scenarios as a single run. An example of what I'm talking about is the following protocol that has been working very well for me on a 3.6 Å strucutre: - ~6 rounds of refinement of TLS, a single group B-factor and occupancies (the latter for a very small set of residues, mostly low-occupancy lead ions) with positions fixed - ~8 rounds of TLS and individual B-factor refinement, still with positions fixed and with no further occupancy refinement - ~8 rounds of TLS, B-factor and position refinement with torsion-angle restraints to the starting model - ~8 rounds of position refinement with no restraints other than standard stereochemistry and metal bonds. I know that all of this could be scripted quite easily from the command line, but it would be fantastic to be able to queue up such a protocol as a single continuous job in the GUI. Best regards, Tristan

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Command line version of Reflection_file _editor
by Rahel Woldeyes 29 Feb '16

29 Feb '16

Hi all, I was wondering if anyone has implemented command line compatible version of phenix.reflection_file_editor . Thanks! Rahel

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Command line version of Reflection_file _editor
by Rahel Woldeyes 29 Feb '16

29 Feb '16

Hi all, I was wondering if anyone has implemented command line compatible version of phenix.reflection_file_editor . Thanks!

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Simulated annealing composite omit map
by Appu kumar 29 Feb '16

29 Feb '16

Hello All, I am trying to make the simulated annealing composite omit map for a protein ligand complex at 4.37A resolution. I think, Simulated annealing is harsh and rendering the protein distorting a lot as is evident from the helix turning into the some random structure. In order to avoid this protein distortion in protein backbone, do I need to fix some weight or specific parameter or provide reference structure and put harsh weight ? Any advice or suggestions would be much appreciated. Appu

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Phaser-EP log file
by Nishant Pandey 28 Feb '16

28 Feb '16

Hi,I have a confusion regarding solving iodine SAD-data in Phaser-EP.1. GUI result shows Log-likelihood gain: 115037.70 and FOM: 0.527. But in log file SAD Refinement Table (Sorted) ----------------------------- SET SpaceGroup FOM Log-Likelihood Rfac Composition I # 1 P 21 21 2 0.53 -115038 69.4 23 Why there is negative value of Log-Likelihood in log file? Is Log-Likelihood and Log-likelihood gain is two different things?Has Phaser solved it? When I feed these results to Autobuild, the model was ~80 % complete with Rfree and Rwork of 0.3171 and 0.2754 and Model Map correlation 0.74. Model was further refined in phenix.refine upto Rfree = 0.27. 2. When I am solving same dataset with Autosol and Autobuild, the dimer orientation have changed? Is this 'normal' or one of the solution is wrong and if it then which one should choose to refine further? Thanks in advance.

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phenix.elbow with Gamess, no cif restraint file
by Dyda 26 Feb '16

26 Feb '16

Hi All, I'm clearly doing something wrong, but don't know what. Trying to run elbow with Gamess from the command line for "myligand" but no .cif file is produced. The input is a pdb file of the ligand, this the best I have. The command line: phenix.elbow --all-residues --do-all --gamess --basis=3D"3-21G" myligand.pdb > elbow.out & Everything seems to be OK, Gamess is found and run: > more elbow.out ------------------------------------------------------------------------------ electronic Ligand Builder & Optimisation Workbench (eLBOW) 1.10.1-2155 None - Nigel W. Moriarty (NWMoriarty(a)LBL.Gov) ------------------------------------------------------------------------------ Random number seed: 3628800 Initial processing time : 0.01 seconds 0:00 Parsing Parsing Parsing Parsing Parsing Parsing Parsing Parsing Parsing P Input format is PDB MoleculeClass : C:15 O: 6 Cr: 1 (PDB format) 22 atoms 0 bonds 0 angles 0 dihedrals 0 rings 0 chirals Predicted memory usage by semi-empirical method : 41Mb Timing estimates Python portion / ATP : 62% c++ optimisation cycle / ATP : 47% Hydrogens may be required to determine the correct bonding Residue has metal at the centre of a coordination sphere. Using input geometry to generate restraints. Hydrogens may not be added. 0:10 Hydrogenise Hydrogenise Hydrogenise Hydrogenise Hydrogenise Hydrogenise H 1:49 ReCentre molecule for optimisation ReCentre molecule for optimisation ReC Optimisation software : GAMESS Quantum method : UHF Quantum basis set : 3-21G Opt steps : 60 Opt macro steps : 3 Searching for flowchart file: flowchart.py searching: /usr/local/apps/Phenix/1.10.1-2155/phenix-1.10.1-2155/modules/elbow ****************************************************************************** filename : /usr/local/apps/Phenix/1.10.1-2155/phenix-1.10.1-2155/modules/elbow/flowchart.py FOUND ****************************************************************************** searching: /usr/local/apps/Phenix/1.10.1-2155/phenix-1.10.1-2155 searching: /home/dyda/.elbow searching: /home/dyda searching: /spin1/users/dyda/myligand Machine has 24018 Mb total memory 14687 Mb free memory Setting 1000 Mb max memory usage Searching for template run file: GAMESS.csh searching: /spin1/users/dyda/myligand ****************************************************************************** filename : /spin1/users/dyda/myligand/GAMESS.csh FOUND ****************************************************************************** Using /spin1/users/dyda/myligand/GAMESS.csh as input run file template all .inp, .dat, .gam files are produced, no errors, but no cif file. Thanks. Fred [32m******************************************************************************* Fred Dyda, Ph.D. Phone:301-402-4496 Laboratory of Molecular Biology Fax: 301-496-0201 DHHS/NIH/NIDDK e-mail:[email protected] Bldg. 5. Room 303 Bethesda, MD 20892-0560 URGENT message e-mail: 2022476710(a)mms.att.net Google maps coords: 39.000597, -77.102102 http://www2.niddk.nih.gov/NIDDKLabs/IntramuralFaculty/DydaFred *******************************************************************************[m

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script to calculate phase error
by Kaushik Hatti 26 Feb '16

26 Feb '16

Hello, I understand Phase error is written out after phenix.refine. For a particular case, I need to calculate phase error during different stages of model building (before refinement). Is there a script available which could calculate phase error given a model(PDB) and structure factors (MTZ) files? Thanks, Kaushik -- Stupidity is everyone’s birthright. However, only the learned exercise it! --Kaushik (28Oct2014)

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Separate cif files for the same nucleoside analog in it's monophosphate or triphosphate form?
by Zhe Li 26 Feb '16

26 Feb '16

Hi, I’m working on several protein/ligand structures, where the ligand is a novel nucleoside analog inhibitor. In each structure the ligand is either non-covalently bound as a ligand-5’-triphosphate (TP), or covalently bound to the protein as ligand-5’-monophosphate (MP). Do I need to create different cif file for ligand-MP and ligand-TP, or phenix can recognize the phosphates and there is no need for that? Thank you.

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Multiple conformations
by Alejandro Virrueta 25 Feb '16

25 Feb '16

This is not exactly phenix specific, but I was wondering what are some commonly used methods to determine and validate the presence/occurrence of multiple conformations for a given amino acid? I am currently refining (for 5 cycles) a pdb with the occupancy of atoms of a specific residue set to 0, and then looking at the difference density map contoured to 3 sigma for extra density. Is this somewhat correct? What else could/should I do? Would using OMIT maps help? (What are OMIT maps, and how do I generate them?) Thanks, Alex (not a crystallographer)

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