October 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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refining with f' and f" values
by Subhani Bandara 01 Nov '12

01 Nov '12

Hi Everyone, I have a structure with heavy metals which I would like to refine anomalous scattering factors. I could get the f' and f" values from Autosol, when I gave the atom name and wavelength. But when I ran refinement with anomalous scattering giving .mtz file and pdb file from pHENIX refinement I got the error "Invalid combination-F-obs not anomalous, provide anomalous reflections or fix all f" values. Then I used reflection file editor of GUI to create a mtz file that has anomalous data using the original reflection file and the mtz file of refinement. But still it gives an error. I must be doing something wrong, but cannot figure out what that is. Thanks in advance for any help. Subhani

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"H" atom refining occupancy with previous altconf residue in sequence
by Alexander Scouras 01 Nov '12

01 Nov '12

After a series of residues (1+) with alternate conformations, the H atom of the next residue seems to lock its occupancy to that of the final conformation of the previous residue. Hence I'm getting several H's with 0.1-0.5 occupancy on single conformation residues, where the entire rest of the residue has occupancy 1. This happens after every altconf series, and showed up in two separate structures I've worked on this week. Within a series of 2+ residues with altconfs, the H's refine correctly with their altconf groups. So it isn't just that all subsequent residue's H's are getting overridden. This behavior seems to have started with 1.8.1-1168, or at least previous refinements of the same structure didn't do this. 64 bit build on Retina MBP running OS X 10.8.2. I couldn't google any reference to this behavior, so assuming it's a new bug I can send along source files. Below I've pasted a couple residues from one of my PDBs. I added a ***** to mark the offending H with the wrong occupancy. -Alex Scouras ATOM 668 N CMET A 29 -17.970 6.464 59.720 0.21 10.72 N ANISOU 668 N CMET A 29 1641 1300 1133 -328 -379 -50 N ATOM 669 CA CMET A 29 -17.578 5.189 60.316 0.21 9.05 C ANISOU 669 CA CMET A 29 1545 882 1012 -248 -350 -140 C ATOM 670 C CMET A 29 -17.248 5.317 61.797 0.21 7.83 C ANISOU 670 C CMET A 29 1363 666 947 173 -134 166 C ATOM 671 O CMET A 29 -17.496 4.395 62.578 0.21 7.92 O ANISOU 671 O CMET A 29 1187 751 1071 371 -145 338 O ATOM 672 CB CMET A 29 -16.376 4.609 59.573 0.21 9.09 C ANISOU 672 CB CMET A 29 1561 834 1059 -243 -283 -203 C ATOM 673 CG CMET A 29 -16.681 4.210 58.145 0.21 9.05 C ANISOU 673 CG CMET A 29 1529 756 1154 -28 -331 -235 C ATOM 674 SD CMET A 29 -18.049 3.042 58.009 0.21 13.05 S ANISOU 674 SD CMET A 29 2356 1325 1279 -218 -284 -50 S ATOM 675 CE CMET A 29 -17.505 1.757 59.124 0.21 12.06 C ANISOU 675 CE CMET A 29 1866 1485 1232 -630 -667 420 C ATOM 676 H CMET A 29 -17.333 6.878 59.318 0.21 12.87 H ATOM 677 HA CMET A 29 -18.320 4.557 60.216 0.21 10.86 H ATOM 678 HB2CMET A 29 -15.671 5.275 59.551 0.21 10.91 H ATOM 679 HB3CMET A 29 -16.069 3.819 60.044 0.21 10.91 H ATOM 680 HG2CMET A 29 -16.916 5.004 57.640 0.21 10.86 H ATOM 681 HG3CMET A 29 -15.894 3.794 57.761 0.21 10.86 H ATOM 682 HE1CMET A 29 -18.164 1.059 59.140 0.21 14.48 H ATOM 683 HE2CMET A 29 -16.666 1.409 58.813 0.21 14.48 H ATOM 684 HE3CMET A 29 -17.401 2.130 60.002 0.21 14.48 H ATOM 685 N MET A 30 -16.667 6.445 62.187 1.00 6.77 N ANISOU 685 N MET A 30 1361 564 647 -30 -56 18 N ATOM 686 CA MET A 30 -16.416 6.699 63.606 1.00 7.66 C ANISOU 686 CA MET A 30 1362 946 601 -42 -173 2 C ATOM 687 C MET A 30 -17.759 6.724 64.367 1.00 7.62 C ANISOU 687 C MET A 30 1310 944 641 -9 -24 -22 C ATOM 688 O MET A 30 -17.852 6.212 65.486 1.00 9.05 O ANISOU 688 O MET A 30 1571 1151 718 84 98 231 O ATOM 689 CB MET A 30 -15.620 7.987 63.790 1.00 7.65 C ANISOU 689 CB MET A 30 1299 894 714 26 -120 -166 C ATOM 690 CG MET A 30 -14.229 7.965 63.231 1.00 8.62 C ANISOU 690 CG MET A 30 1464 1072 741 31 -163 -10 C ATOM 691 SD MET A 30 -13.130 6.745 64.006 1.00 9.04 S ANISOU 691 SD MET A 30 1555 961 919 105 -180 -94 S ATOM 692 CE MET A 30 -12.812 7.527 65.563 1.00 9.77 C ANISOU 692 CE MET A 30 1540 1284 889 150 -190 -62 C ATOM 693 H MET A 30 -16.395 7.062 61.653 0.21 8.12 H ***** ATOM 694 HA MET A 30 -15.872 5.965 63.962 1.00 9.19 H ATOM 695 HB2 MET A 30 -16.099 8.709 63.352 1.00 9.18 H ATOM 696 HB3 MET A 30 -15.550 8.173 64.739 1.00 9.18 H ATOM 697 HG2 MET A 30 -14.278 7.758 62.284 1.00 10.35 H ATOM 698 HG3 MET A 30 -13.831 8.840 63.354 1.00 10.35 H ATOM 699 HE1 MET A 30 -12.228 6.968 66.079 1.00 11.73 H ATOM 700 HE2 MET A 30 -12.397 8.378 65.406 1.00 11.73 H ATOM 701 HE3 MET A 30 -13.644 7.648 66.026 1.00 11.73 H

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Re: [phenixbb] Troublesome molecular replacement
by Yuri 29 Oct '12

29 Oct '12

Nat, Just a few simple thoughts: --1) Are you certain about the space group, and did you try letting --Phaser pick one for you? (It sounds like you did, but I can't tell --from your description.) I searched for a solution in all possible space groups in P 4. I thought I was certain of the space group, but maybe not... --2) How much refinement did you run to get an R-free of 42$, and did --you already try running AutoBuild with rebuild-in-place turned off? --Refinement alone may not have the radius of convergence you need. True, I only did a couple of rounds of rebuild/refine --3) What is the sequence identity? My model is a point-mutant of the crystal. --4) Are you using the latest version of Phenix? Phaser has had TNCS --support for almost a year now but I keep hearing from people who are --using ancient versions... I am using the latest official PHENIX built. --- -- Yuri Pompeu

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Troublesome molecular replacement
by Yuri 29 Oct '12

29 Oct '12

Dear community, I recently collected on a crystal that diffracted pretty well to 2.0 A. It indexes and scales fairly well in P 4 21 2 with cell dimensions 100, 100, 200. This would predict 4 molecules/ASU. I found a MR solution in P 41 21 2 but it does not refine very well Rfree =42%. Xtriage detects strong peaks at 0,0,0.25 for Translational NCS. Any suggestions on how to go about this one? Thanks -- Yuri Pompeu

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autobuilding homomers
by Ingemar Andre 29 Oct '12

29 Oct '12

I have a question about the proper procedure for building homomers. My test case is a trimeric coiled-coil with 3-fold symmetry (trimer in assymetric unit). My input model is a trimer with three chains (A,B,C) with identical sequence. If I run phenix autobuild (rebuild_in_place=False) with this model I get a structure with decent R/Rfree. However, there are some issues: 1) Helix 1 consists of chain A in the output structure. There is a jump in the sequence number for chain A at the end. However, disregarding this chain break the full sequence is correct for helix 1. 2) Helix 2 consists of chain B + C in the output structure. The chain B has the correct sequence for helix 2. Chain C has partly the right sequence for helix 2. 3) Helix 3 consists of chain C in the output structure. Chain C has partly the correct sequence for helix 3. Lots jumps in the sequence numbering. GIven that I know its has three subunits with identical sequences I gather it should be possible to have autobuild generate structures with three chains with identical sequences. I have tested a few things. With and without giving it the sequence file corresponding to the sequence of a monomer. With and without enforcing ncs based on the input model (find_ncs=False input_ncs_file=find_ncs.ncs_spec). I am never able to build sequence-symmetric structures with rebuild_in_place=False for any homomer I have tried to build. I have limited experience with phenix so it is likely I am missing something obvious. In any case, I would appreciate your input on this. Best regards, Ingemar

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Parallella
by Morten Groftehauge 27 Oct '12

27 Oct '12

Hi guys, So the Parallella project seems like it is going forward (with the smaller processor first off) http://www.kickstarter.com/projects/adapteva/parallella-a-supercomputer-for… I figure that phenix would have problems with low amount of RAM but are there other reasons that Phenix and Parallella might not play well together? Supposedly ships in May, btw. Cheers, Morten -- Morten K Grøftehauge, PhD Pohl Group Durham University

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