- phenixbb - phenix-online.org

ncs restraints
by Timothy Springer 08 Dec '10

08 Dec '10

Hi, I am using NCS restraints for 4 copies of a molecule at 3.05 Å. We are using the standard weights: coordinate_sigma = 0.05 b_factor_weight = 10 and the 4 molecules look identical. What are suggested values for looser restraints? One of my colleagues said that varying them did not make a difference- ncs was still very strict. Is there a way to make them less strict? Thanks, Timothy A. Springer, Ph.D.

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phaser version
by Bryan Lepore 08 Dec '10

08 Dec '10

using dev-596 from source, i see `phenix.phaser --version` is Phaser-2.2.4 (svn ) that's true for dev-601 (Intel binary) also. the phaser wiki says 2.3 is the latest, and to compile it from the phenix distribution. so... wondering how to get phaser 2.3 (before asking questions about ep_sad...) -Bryan

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anyone with a scalepack file with R3 or R32 using rhombohedral axes?
by Ralf W. Grosse-Kunstleve 08 Dec '10

08 Dec '10

I'm looking for a little help from the phenix user community. Does anyone have a scalepack output file with data in space group R3 or R32 using rhombohedral axes, i.e. unit cell parameters a=b=c, alpha=beta=gamma? What is the space group symbol in the file? I'm only interested to know this for files that are the direct output of scalepack. I'd like to verify that this part of the scalepack documentation is actually true: http://www.hkl-xray.com/hkl_web1/hkl/manual_online.pdf Page 139: 146 R3 R3 in hexagonal setting 446 H3 R3 in primitive setting 155 R32 R32 in hexagonal setting 455 H32 R32 in primitive setting If this is actually true, it is the exact opposite of what's used by the PDB. Thanks in advance for feedback. Ralf

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modelling of a novel protein
by intekhab alam 08 Dec '10

08 Dec '10

Hi I am trying to solve the structure of RNA polymerase in complex with its protein primer. The size of protein primer is 70 amino acids which i complexed with the polymerase and collected a data of the complex crysta at 2.3A. The space group is C2 and after Molecular replacemnet with full length polymerase in auto MR i got 3 subunits in ASU. The parameters of MR solution RFZ=71.5 TFZ=41.2 PAK=0 LLG=8812 suggests that the solution is correct. I used autobuild for model building which gave me the model of the polymerase as well as some extra density that i am considering as the other protein. After several round of refinemnt i have R and R free of 27and 32 respectively. My queries: 1. I want to know ,how can i improve my R as well as R free. 2. How can i model other protein as the density is weak and not complete, how can i improve the map of the other protein so that i can b ebale to trace the c-alpha backbone, i was able to model only 10 amino acids so far. Please guide. Regards -- INTEKHAB ALAM LABORATORY OF STRUCTURAL BIOINFORMATICS KOREA UNIVERSITY, SEOUL

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distorted (collapsed) zinc-finger motifs
by Hasan Demirci 07 Dec '10

07 Dec '10

Hi, I am in the middle of refining a 3.5 A (low resolution) ribonucleo-protein complex structure. Two of the proteins in this complex contain "zinc-finger" motif. These zinc-finger motifs instead of forming a cysteine-zinc interactions, cysteines are forming di or in these case tetra-sulfide bridges. Initially, zinc is centered but after refinement 4 cysteines come out collapsed and forming covalent bonds to each other and also distorted and zinc is not at the center anymore. Below is the phenix.refine zn_link.param file I am using. Many thanks for advice, Hasan Demirci ---------------------------------------------------------------------------- refinement.pdb_interpretation { disulfide_distance_cutoff = 0.1 } refinement.pdb_interpretation.apply_cif_link { data_link = ZN-CYS residue_selection_1 = chain D and resname ZN and resid 306 residue_selection_2 = chain D and resname CYS and resid 9 } refinement.pdb_interpretation.apply_cif_link { data_link = ZN-CYS residue_selection_1 = chain D and resname ZN and resid 306 residue_selection_2 = chain D and resname CYS and resid 12 } refinement.pdb_interpretation.apply_cif_link { data_link = ZN-CYS residue_selection_1 = chain D and resname ZN and resid 306 residue_selection_2 = chain D and resname CYS and resid 26 } refinement.pdb_interpretation.apply_cif_link { data_link = ZN-CYS residue_selection_1 = chain D and resname ZN and resid 306 residue_selection_2 = chain D and resname CYS and resid 31 } refinement.pdb_interpretation.apply_cif_link { data_link = ZN-CYS residue_selection_1 = chain N and resname ZN and resid 307 residue_selection_2 = chain N and resname CYS and resid 24 } refinement.pdb_interpretation.apply_cif_link { data_link = ZN-CYS residue_selection_1 = chain N and resname ZN and resid 307 residue_selection_2 = chain N and resname CYS and resid 27 } refinement.pdb_interpretation.apply_cif_link { data_link = ZN-CYS residue_selection_1 = chain N and resname ZN and resid 307 residue_selection_2 = chain N and resname CYS and resid 40 } refinement.pdb_interpretation.apply_cif_link { data_link = ZN-CYS residue_selection_1 = chain N and resname ZN and resid 307 residue_selection_2 = chain N and resname CYS and resid 43 } # data_link_ZN-CYS # loop_ _chem_link_bond.link_id _chem_link_bond.atom_1_comp_id _chem_link_bond.atom_id_1 _chem_link_bond.atom_2_comp_id _chem_link_bond.atom_id_2 _chem_link_bond.type _chem_link_bond.value_dist _chem_link_bond.value_dist_esd ZN-CYS 1 ZN 2 SG single 2.340 0.020 loop_ _chem_link_angle.link_id _chem_link_angle.atom_1_comp_id _chem_link_angle.atom_id_1 _chem_link_angle.atom_2_comp_id _chem_link_angle.atom_id_2 _chem_link_angle.atom_3_comp_id _chem_link_angle.atom_id_3 _chem_link_angle.value_angle _chem_link_angle.value_angle_esd ZN-CYS 1 ZN 2 SG 2 CB 109.000 3.000 ---------------------------------------------------------------------------------------------------- -- Hasan DeMirci, Ph.D. Postdoctoral Fellow Department of Molecular Biology, Cellular Biology & Biochemistry Brown University 185 Meeting Street Providence, RI 02912 (401) 863-3652 lab (SFH) (401) 863-6124 lab (ship st) (401) 226-7852 cell Hasan_DeMirci(a)Brown.edu demircha99(a)gmail.com

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Re: [phenixbb] Using Reference Structure in Phenix Refine
by John Pascal 05 Dec '10

05 Dec '10

Got it! Thank you, Pavel and Jeff. Best, John -- John Pascal, PhD ph 215.503.4596 Assistant Professor fx 215.923.2117 Thomas Jefferson University Biochemistry & Molecular Biology 233 South 10th Street, BLSB 804 Philadelphia, Pennsylvania 19107 ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

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Using Reference Structure in Phenix Refine
by John Pascal 05 Dec '10

05 Dec '10

Hello Everyone, I am refining against low resolution data, and I would like to use a higher resolution model that is available as a reference structure. There are multiple copies of the molecule in the asymmetric unit, each with a different chain ID. Does the reference PDB file need to contain multiple copies, such that there is a match for each chain (e.g. RESIDs and SEGIDs)? Or does phenix figure out that the reference structure refers to several copies of the molecule, and you only need a single copy in the reference molecule PDB file? Or will NCS restraints take care of this? Thanks. -John -- John Pascal, PhD ph 215.503.4596 Assistant Professor fx 215.923.2117 Thomas Jefferson University Biochemistry & Molecular Biology 233 South 10th Street, BLSB 804 Philadelphia, Pennsylvania 19107 ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

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Can PHENIX write the peak list to a PDB file?
by Joe Krahn 04 Dec '10

04 Dec '10

PHENIX has an option to find positive and negative peaks, but only lists them in the log file along with the residue they are closest to. Is it possible to write out the actual peak coordinates, such as to a PDB file? Thanks, Joe Krahn

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heavy atom search within phaser molecular replacement
by Bryan Lepore 03 Dec '10

03 Dec '10

i know that phaser will find heavy atoms in autosol, and that "MR-SAD" can be run as two separate steps, such that with some scripting, one could in principle cycle through a bunch of heavy atom searches using MR phases. however, it is not clear to me whether phaser can be run such that e.g. the refined MR solutions can have their anomalous Fourier's searched for peaks in a single MR job. seems possible in principle - before i go trying this, any comments would be appreciated.... i.e. run heavy atom searches as part of molecular replacement, for convenience. hope that makes sense. -Bryan

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Issue with phenix.superpose_maps
by Stephen Graham 03 Dec '10

03 Dec '10

Hi all, I'm trying to use phenix.superpose_maps through the GUI to get superposed maps covering the same region of NCS-related chains A and B for a figure. I have used PDB Tools to split the model into two files with only chain A or chain B. However, when I run superpose_maps specifying the two individual chains for the input PDB files but the same mtz file for the map coefficients I only get one output map (I think it overwrites the output file...). Selected input from the generated .eff file is as follows: input_files { map_1 = "/home/stepheng/blah/Native_refine_6_map_coeffs.mtz" labels_1 = 2FOFCWT,PH2FOFCWT map_2 = "/home/stepheng/blah/Native_refine_6_map_coeffs.mtz" labels_2 = 2FOFCWT,PH2FOFCWT pdb_1 = "/home/stepheng/blah/Native_refine_6_chainA.pdb" d_min_1 = None pdb_2 = "/home/stepheng/blah/Native_refine_6_chainB.pdb" d_min_2 = None output_dir = "/home/stepheng/blah" } And the end of the output is as follows: saving CCP4 map to Native_refine_6_map_coeffs_superposed.ccp4 Wrote Native_refine_6_chainA_superposed.pdb Wrote Native_refine_6_map_coeffs_superposed.ccp4 saving CCP4 map to Native_refine_6_map_coeffs_superposed.ccp4 Wrote Native_refine_6_chainB_superposed.pdb Wrote Native_refine_6_map_coeffs_superposed.ccp4 A bug? Stephen P.S. Incidentally, is there any reason you write both maps in a P1 box rather than putting map 2 on top of map 1 in the position of the first (reference) model? The latter would be more convenient as you can then re-use your carefully chosen pymol viewing matrices for all figures... -- Dr Stephen Graham 1851 Research Fellow Cambridge Institute for Medical Research Wellcome Trust/MRC Building Addenbrooke's Hospital, Hills Road Cambridge, CB2 0XY, UK Phone: +44 1223 762 638

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