March 2011 - phenixbb - phenix-online.org

scattering factors
by Goragot Wisedchaisri 21 Jun '11

21 Jun '11

Hi, I am new to Phenix but I have used Solve/Resolve in the past. I am currently using Phenix 1.6.2 and I have electron diffraction data to ~2A from a 300kV electron microscope that I would like to use Autobuild and phenix.refine to iteratively rebuild and refine my partial structure. I have a file containing electron scattering factors for 300kV EM that has been used successfully for refinement with CNS before for electron diffraction data. How can I tell Phenix to use electron scattering factors during refinement? I think currently Phenix has 4 choices for X-ray and neutron scattering factors but not for electron scattering. Is there a good way to implement electron scattering factors into phenix library? Any suggestions are welcome. George Wisedchaisri

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The individual site refinement for Low resolution data (~3.8A)
by Zhang yu 14 Apr '11

14 Apr '11

Dear phenixer, Phenix suggested "Individual site" refinement is only suitable for high or midi resolution data (<3.5A). What is the alternate strategy to refine the atom coordinates of low resolution data? Yu

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phenix.maps2mtz
by Yarrow Madrona 02 Apr '11

02 Apr '11

Hello, I am running phenix-1.7-650 and would like to generate a ccp4 map for use in pymol from an mtz. I can type: phenix.maps2mtz file.mtz but I cannot figure out how to limmit the selection to a single chain (chain A). I guess you can do this in maps.params but I wanted to keep it simple without having to use the sca file. Thank you. -Yarrow -- Yarrow Madrona Graduate Student Molecular Biology and Biochemistry Dept. University of California, Irvine Natural Sciences I, Rm 2403 Irvine, CA 92697

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"FOM" or HL coeffs from model?
by Phoebe Rice 01 Apr '11

01 Apr '11

How can I get phenix to spit out not just PhiModel but an estimated FOM or fake HL coefficients (without experimental phases - just based on how badly my model agrees with FOBS)? And I'd like the weights in their own personal mtz column(s), not just precombined in a "weighted phi" column. In case anybody cares why, I'd like to use solvent massaging and domain-wise averaging to remove bias from a low-resolution model-phased map, preferably with DM, unless anybody has a better suggestion. I did rigid body, TLS, etc on the model in phenix, so it seems like phenix has already calculated all the info I want if I could only squeeze it out. thanks, Phoebe ===================================== Phoebe A. Rice Dept. of Biochemistry & Molecular Biology The University of Chicago phone 773 834 1723 http://bmb.bsd.uchicago.edu/Faculty_and_Research/01_Faculty/01_Faculty_Alph… http://www.rsc.org/shop/books/2008/9780854042722.asp

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low resolution map weirdness with newer releases
by Scott Classen 01 Apr '11

01 Apr '11

Something changed between build 432 and 486 that made my low resolution maps look much crappier. See attached tiff. See if you can guess which map was produced by the release 486. def file looks more or less like this (from a --diff-params): refinement { crystal_symmetry { unit_cell = top secret space_group = top secret } input { pdb { file_name = "../4_23_003.pdb" } xray_data { file_name = "../4_23.sca.mtz" labels = "4_23.sca,SIG4_23.sca" high_resolution = 3.9 r_free_flags { file_name = "../4_23.sca.mtz" label = "R-free-flags" test_flag_value = 1 } } } output { prefix = "test-486" serial = 1 } refine { strategy = *individual_sites individual_sites_real_space rigid_body \ individual_adp group_adp tls occupancies group_anomalous sites { individual = "chain A and resseq 100:107" individual = "chain B and resseq 500:507" individual = "chain E and resseq 100:107" individual = "chain F and resseq 500:507" individual = "chain C and resseq 111:117" individual = "chain D and resseq 111:117" individual = "chain G and resseq 111:117" individual = "chain H and resseq 111:117" individual = "chain C and resseq 63:68" individual = "chain D and resseq 63:68" individual = "chain G and resseq 63:68" individual = "chain H and resseq 63:68" rigid_body = "chain A" rigid_body = "chain B" rigid_body = "chain C" rigid_body = "chain D" rigid_body = "chain E" rigid_body = "chain F" rigid_body = "chain G" rigid_body = "chain H" } } main { number_of_macro_cycles = 1 secondary_structure_restraints = True random_seed = 3141766 optimize_mask = False } modify_start_model { adp { set_b_iso = 50 } } fake_f_obs { mask { ignore_hydrogens = True } } geometry_restraints.edits { excessive_bond_distance_limit = 20 } mask { ignore_hydrogens = True } simulated_annealing { start_temperature = 300 final_temperature = 200 } target_weights { wxc_scale = 0.4 } ias { b_iso_max = 60 } secondary_structure { h_bond_restraints { substitute_n_for_h = True remove_outliers = False sigma = 0.02 h_o_distance_ideal = 2.95 h_o_distance_max = 5 n_o_distance_ideal = 2.95 n_o_distance_max = 5 } }

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omit map
by intekhab alam 01 Apr '11

01 Apr '11

Hi i generated an iterative build omit map using phenix and the output fule that i got is resolve_composite_map.mtz, but i cannot open this file in coot, what modifications do ineed to open this file in coot. Regards -- INTEKHAB ALAM LABORATORY OF STRUCTURAL BIOINFORMATICS KOREA UNIVERSITY, SEOUL

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Bulk solvent correction
by Ina Lindemann 31 Mar '11

31 Mar '11

Hi, I am refining two crystal structures of the same protein wtih four domains and 687 amino acids. These are the last lines form my log-files after several model building steps - protein altogether fits quite well into the density. But I am confused about these logfiles: 1.Why is there such a big difference between R values with and without bulk solvent correction and anisotropic scale? Start R-work = 0.3765, R-free = 0.5498 (no bulk solvent and anisotropic scale) Final R-work = 0.3733, R-free = 0.5509 (no bulk solvent and anisotropic scale) Start R-work = 0.2356, R-free = 0.2962 Final R-work = 0.2250, R-free = 0.2939 2. (the other structure) Why does the R value without bulk solvent and anisotropic scale decrease so much but with it remains stable? Start R-work = 0.2182, R-free = 0.2856 (no bulk solvent and anisotropic scale) Final R-work = 0.4054, R-free = 0.4223 (no bulk solvent and anisotropic scale) Start R-work = 0.2157, R-free = 0.2827 Final R-work = 0.2147, R-free = 0.2816 I would be very pleased about any helpful comments. Ina Ina Lindemann Philipps-Universität Marburg Pharmazeutische Chemie AG Klebe Marbacher Weg 6 35032 Marburg Tel.: 06421/2825908

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what to do with disordered side chains
by Ed Pozharski 31 Mar '11

31 Mar '11

The results of the online survey on what to do with disordered side chains (from total of 240 responses): Delete the atoms 43% Let refinement take care of it by inflating B-factors 41% Set occupancy to zero 12% Other 4% "Other" suggestions were: - Place atoms in most likely spot based on rotomer and contacts and indicate high positional sigmas on ATMSIG records - To invent refinement that will spread this residues over many rotamers as this is what actually happened - Delet the atoms but retain the original amino acid name - choose the most common rotamer (B-factors don't "inflate", they just rise slightly) - Depends. if the disordered region is unteresting, delete atoms. Otherwise, try to model it in one or more disordered model (and then state it clearly in the pdb file) - In case that no density is in the map, model several conformations of the missing segment and insert it into the PDB file with zero occupancies. It is equivalent what the NMR people do. - Model it in and compare the MD simulations with SAXS - I would assumne Dale Tronrod suggestion the best. Sigatm labels. - Let the refinement inflate B-factors, then set occupancy to zero in the last round. Thanks to all for participation, Ed. -- "I'd jump in myself, if I weren't so good at whistling." Julian, King of Lemurs

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phenix migration
by Xtal_bb 31 Mar '11

31 Mar '11

Hi guys, I have just got a brand new iMac, to replace my MacBook, in which I used to run phenix. I have installed phenix in the new iMac, and copied the directory with all the files of my previous runs. However, what should I migrate to have the projects and previous work recognized by the fresh install? Thanks for the help, ciao s -- Sebastiano Pasqualato, PhD Crystallography Unit IFOM-IEO Campus Cogentech - Consortium for Genomic Technologies via Adamello, 16 20139 - Milano Italy tel +39 02 9437 5172 fax +39 02 9437 5990

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how convert mtz in xplor format
by fulvio saccoccia 30 Mar '11

30 Mar '11

Greetings to all, Does anyone know how convert a .mtz file into a xplor format file? Thanks in advance Fulvio Saccoccia

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