November 2012 - 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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links in phenix summary
by Christian Roth 04 Apr '13

04 Apr '13

Dear all, thanks to the phenix team which helped me a lot to resolve all issues regarding the correct link definitions. I have summarised a few things which one might consider if nonstandard links are necessary. Try phenix ready set to get your links out of the pdb. Do not forget to change the possible LINKR to LINK! Inspect the links and decide if they are useful! Peptide links are automatically incorporated if residues are close (inspect geo file) Non standard peptide links could be created using using an now available alpha release script: elbow.ligand_linking model.pdb Inspect the generated cif file and correct angles and incorporate dihedrals and so on if necessary. Sugar links which exists in the mon_lib.cif should be incorporated using the apply_cif link option like refinement.pdb_interpretation.apply_cif_link { data_link = ALPHA1-4 residue_selection_1 = chain B and resname GLC and resseq 1 residue_selection_2 = chain B and resname GLC and resseq 2 } According to the link definition the C1 oxygen of the following sugar with the higher number must be removed. The automatic incorporation of sugar links will be probably soon available in phenix. Nigel is already working on this. If one want use hydrogens in the refinement, they have to be added previously with ready_set and afterwards the OH4 sugar hydrogen has to be removed before the refinement. For links with symmetry related atoms the symmetry operator must be included in a custom bond definition efinement.geometry_restraints.edits { bond { action = *add delete change atom_selection_1 = chain A and resname HEM and resid 154 and name FE atom_selection_2 = chain A and resname MTO and resid 155 and name O symmetry_operation = -x,y,-z distance_ideal = 2.2 sigma = 0.01 } } The operator can be obtained using iotbx.show_distances your.pdb > all_distances Search for keyword "sym" or from Coot clicking on the symm option. Coot print out the operator and the translation term separately. Both has to be merged in the final operator used in phenix! Christian

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Memory and CPU usage
by Jon Agirre 05 Mar '13

05 Mar '13

Dear community, I'm planning on buying a new macbook for my first abroad postdoc venture, and I'm currently trying decide what amount of RAM & CPU to choose. My question is a little bit intricate: is there any rule of thumb to estimate the needed RAM versus the number of input atoms for any particular refinement type? I'm planning on tackling some big (18,000 residues/asu) refinements but I don't have any estimation as to how many GBs of RAM they might require. The maximum amount of RAM I can install is 16GB, but it is a non-standard configuration that might void Apple's warranty. About the CPU: how scalable are typical phenix processes? Would it be sensible to invest in a quad-core machine with HT? In this particular case, and since HT would present 8 logical cores, would I get any speed up from launching phenix tasks configured for 8 processors instead of 4? Thanks in advance! Jon

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use of the file find_ncs.resolve
by Fred. Vellieux 29 Jan '13

29 Jan '13

Hi all, I do not understand how the file "find_ncs.resolve" has to be fed into the "resolve" part of Phenix. Can it be used in the GUI for an autobuild procedure? Can anyone help on this? Ta very much in advance, F. Vellieux -- F.M.D. Vellieux (B.Sc., Ph.D., hdr) IBS / ELMA 41 rue Jules Horowitz 38027 Grenoble Cedex 01 France Tel: +33 438789605 Fax: +33 438785494

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how to modify C-D bond length restraints in phenix?
by Maxime Cuypers 16 Jan '13

16 Jan '13

Hi, i am refining a perdeuterated neutron structure and have noticed a lot of positive density aside the D atoms on aliphatic and aromatic side chains. just in the alignment of C-D bonds (C-D then +), suggesting that phenix.refine constraints these bond lengths too short in my case. i tried automatic weights for geometry refinement and unrestrained specific C-D refinement but it is not satisfactory. then i found the following funny distances (angströms) in the pdb database neutron structures: 3KYX: program: Phenix.refine D-prot Distances: C-D aromatics = 0.93-0.94 C-D aliph. = 0.98 1CQ2 Program : xplor3.1 D-protein (despite the atoms being labelled as H according to abstract) Distances: C-D aromatics = 1.06-1.08 C-D aliph. = 1.08 4FC1 H-protein Distances: program: Phenix.refine C-H aromatics = 0.93 C-H aliph. = 0.97 1VCX H-protein program: CNS Distances: C-H aromatics = 1.06-1.10 C-H aliph. = 1.09 those neutron C-D/C-H bond lengths in pdb seem pretty much inconsistentto me. So it seems that phenix.refine uses C-D/ C-H bonds restrains that are different to other programs to below 1.0 Ang. ( ca. 0.10 A differences) how can i change the restraints to make it all longer bond lengths for C-D only? with a .cif file? i saw that phenix uses the CCP4 monomer library but the one in : /usr/local/phenix-.../chem_data/mon_lib/list only seem to be applying modifications. any clue on how to specifically modify the restraints parameters on C-D bonds would be very appreciated. Thanks, Maxime

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Specify particular columns from data files on the command line
by Brad C. Bennett 30 Nov '12

30 Nov '12

Hi all (again)- I'm trying to run DEN refinement in Phenix from the command line. How do I specify certain columns from multiple data files (in my case, 2 MTZ files) to be used? For example, the Rfree flags from one and the hkl data from the other. Thanks! Brad C. Bennett Research Associate- Mark Yeager Lab University of Virginia Molecular Physiology and Biological Physics 320 Snyder Building 480 Ray C. Hunt Drive Charlottesville, VA 22908 Email: bcb3b(a)virginia.edu Lab phone: 434-243-2520

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DEN refinement
by Morten Groftehauge 30 Nov '12

30 Nov '12

Hi guys, Two quick questions about DEN refinement: 1) If gamma refines to 0 does that mean that I should run DEN refinement again with the output model? Or should I do a refinement and then another DEN? Since gamma = 0 the refinement should be allowed a possibility of moving the structure further towards the reference restraints in my mind. 2) If gamma refines to 1 it means that my reference model is inappropriate, right? Not really much of a question, I know. And I know that DEN refinement is in beta but it would be nice if you outputted the optimal gamma and weight for the refinement to the GUI. Actually it would be nice if the did that for geometry weights and xray weights too when one optimizes them. Cheers, Morten -- Morten K Grøftehauge, PhD Pohl Group Durham University

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Error starting Phenix on Linux
by Brad C. Bennett 30 Nov '12

30 Nov '12

Hi all- After installing the latest version and release of Phenix (1.8.1-1168) onto our Linux workstation and setting the environment for bash, I get the following error upon trying to launch Phenix from the command line: ImportError: libjpeg.so.62: cannot open shared object file: No such file or directory I've never seen this before (previous versions of Phenix have run fine on this machine) and don't know what this file is exactly and where it should be located. Anyone come across this and know if there is a fix (or if I'm just doing something stupid!). Thanks! Brad C. Bennett Research Associate- Mark Yeager Lab University of Virginia Molecular Physiology and Biological Physics 320 Snyder Building 480 Ray C. Hunt Drive Charlottesville, VA 22908 Email: bcb3b(a)virginia.edu Lab phone: 434-243-2520

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Call for submissions for the Computational Crystallography Newsletter (CCN) January 2013
by Nigel Moriarty 30 Nov '12

30 Nov '12

Folks Calling for articles and short communications of interest to structural biologists. The deadline for publication in the January 2013 issue is 31 December, 2012 but if you can send me drafts before the 15th of December we can get started on generating proofs. The Computational Crystallography Newsletter (CCN) is an electronic newsletter for structural biologists, and is published online every 6 months. Feature articles, meeting announcements and reports can be submitted to me at any time for consideration. Submission of text by email or word-processing files using the CCN templates is requested. Past newsletters and the template are available at www.phenix-online.org/newsletter. Cheers Nigel -- Nigel W. Moriarty, PhD Building 64R0246B, Physical Biosciences Division Lawrence Berkeley National Laboratory Berkeley, CA 94720-8235 Phone : 510-486-5709 Email : NWMoriarty(a)LBL.gov Fax : 510-486-5909 Web : CCI.LBL.gov

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choosing Rfree set with NCS and twinning
by vincent Chaptal 30 Nov '12

30 Nov '12

Dear phenixbb, I am using the "reflection file editor" in phenix 1.8.1-1168 to generate my test set (with the GUI). I have NCS so I ticked the box "assign test set in thin resolution shells". I also have twinning, and want to have my Rfree not biased by twin related reflections. I guess the option "use lattice symmetry to generate test set" is the one I should use for this purpose? I couldn't find much information online about this option. No log file has been generated so I can't check what happened. I am supposing xtriage is ran in the background and if a twin law is found, then used to generate the test set. My output from xtriage is: Statistics depending on twin laws ----------------------------------------------------------------- | Operator | type | R obs. | Britton alpha | H alpha | ML alpha | ----------------------------------------------------------------- | -k,-h,-l |PM| 0.249| 0.272| 0.246| 0.200| ----------------------------------------------------------------- And indeed if I check in mtzdmp the output mtz, reflections in the test set are related by (-k, -h, -l); disclaimer: I only checked in the plane (h,k,0). I would like to be sure my Rfree is generated correctly. Alternatively, what would happen when multiple twin laws are available? Is the most probale used? Is it possible to specify the editor which law to use? Thank you for your help. Vincent -- Vincent Chaptal, PhD Institut de Biologie et Chimie des Protéines Drug-resistance modulation and mechanism Laboratory 7 passage du Vercors 69007 LYON FRANCE +33 4 37 65 29 01 http://www.ibcp.fr

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