April 2013 - phenixbb - phenix-online.org

phenix.refine - blocking sorry error
by Maxime Cuypers 24 Apr '13

24 Apr '13

hello, i just installed the latest buid of phenix : 1356 i now get the following error in phenix.refine - this was ok with previous version ' Sorry: Your refinement strategy includes anisotropic ADPs for hydrogen atoms refined individually; hydrogens should be left as isotropic even for individual refinement. ' which is the new specific command to add to the .params file that will force anisotropic refinement of deuteriums please? PS: this is needed for my neutron structure refinement. thanks for your help -- Dr. Maxime Cuypers Institut Laue Langevin (ILL), Deuteration lab Rue Jules Horowitz, 6, BP 156 38042 Grenoble cedex 9 France

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Clashes while searching second copy using phaser.AUTOMR
by Rojan Shrestha 23 Apr '13

23 Apr '13

Hello, I have same problem as in the following link which is the previous thread in this bb. If you solved the problem who posted, please let me know the solution how it can be tackled. http://www.phenix-online.org/pipermail/phenixbb/2009-April/013136.html I am trying to find 6 copies in ASU. The space group of diffraction set is P3121. I have obtained one copy with high TFZ scores (18.5) without clashes. However, while searching for second copy, Phaser gave so many clashes with no solution. As I read in above thread, it could be due to parallel pseudo-translation symmetry. Can somebody suggest me to overcome this type of problem? Regards, Rojan

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ICSG 2013 Abstract Deadline extended to May 15, 2013: International Conference on Structural Genomics - Structural Life Science
by Terwilliger, Thomas C 22 Apr '13

22 Apr '13

Dear Colleagues, We hope that you are planning to attend the International Conference on Structural Genomics 2013, which will be held in Sapporo, Hokkaido, Japan, July 29th – August 1st, 2013. ICSG2013-SLS is intended to provide an overview for the most recent developments in Structural Genomics and its impact on research in biology, medicine and disease, and to foster international collaboration among researchers. Five oral presentations will be chosen from the posters, and four poster prizes will be awarded (one HKL Research Best Technology Poster Prize and three Journal of Structural and Functional Genomics Poster Prizes)! Please submit your abstracts by May 15, 2013! You can see all the details of the conference at: http://www.c-linkage.co.jp/ICSG2013 The scientific topics covered in ICSG2013-SLS include the wider life science research fields with particular attention to drug discovery (small molecules and biopharmaceuticals), biotechnology and industrial issues while keeping strength in the high-throughput technologies and integration of hybrid methods. These technologies are now leading to the new field of “Structural Life Science”. In order to widen the opportunity to junior researchers to study more, we have organized several satellite workshops before ICSG2013- SLS (during the day on July 29, 2013). The topics will include “Small molecule screening”, “Automation of X-ray Structure Determination”, “Cell-free Protein Production”, “Automated NMR methods”, "Eukaryotic expression", “Interaction analyses" and "Bioinformatics”. We hope you also find the satellite workshops are informative and productive. The conference will be held in Keio Plaza Hotel Sapporo, in walking distance of Hokkaido University's main campus and Sapporo station. The summer in Sapporo is a great time to stay and enjoy the cool summer night of Japan. ICSG2-13-SLS is partially supported by the Grant-in-Aid for Scientific Research on Innovative Areas; “Structural Cell Biology”, “Intrinsically Disordered Protein” and “Transient Macromolecular Complexes”, from Ministry of Education, Culture, Sports, Science and Technology (MEXT) . We are looking forward to welcoming you to Sapporo this summer! Sincerely yours, Katsumi Maenaka, Ph.D. Chair, International Conference on Structural Genomics 2013 -Structural Life Science- (ICSG2013-SLS) Laboratory of Biomolecular Science and Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Japan Soichi Wakatsuki Chair of Program Committee, ICSG2013-SLS Photon Science, SLAC National Accelerator Laboratory Department of Structural Biology School of Medicine Stanford University The International Structural Genomics Organization Executive Committee Shigeyuki Yokoyama Dino Moras Joel Sussman Jennifer Martin Aled Edwards Tom Terwilliger

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Refinement of perfect twined data of P31/P32
by miyatake 22 Apr '13

22 Apr '13

Hello, Phenix users, Now I'm triying to refine almost perfect twining data (mixing of P31 and P32). It has a twining operation of (h, k, l) = (-h, -k, l), detected by the xtriage program. The data qualigy seems to be good, deflacting to 1.6A resolution with Rmerge ~ 5%. When I refined the MR structures with phenix.refine, however, the model geometries have been worse as over the 20% residues fall into disallowed Ramachandran region, and Rfree stacked around 30%. I tried many options such as real space refinement, SA, bad rotamer fixation, NCS restrain,,.., but they seem to be not so effective as usual twininig cases.. One molecule consists of 202 residues, and three molecules are inolved in AU. Of course, I used the twin option (-h, -k, l) during the refinement. Manual collection of the models could not improve the model anymore. Would anyone please advise me how should I refine the twinned data? Sincerely, Hideyuki, M.

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Turn off non-bonded interactions to measure distance in case of unknown interaction
by Edward A. Berry 22 Apr '13

22 Apr '13

I have a phenix-specific question and a general chemistry question. In a ligand-bound structure, S in an aromatic ring (substituted thiophene) may be H-bonding NH1 of arginine guanidino group. The general question is whether thiophene S can act as H-bond acceptor (assuming one lone pair is in the aromatic pi system for a total of 6 e, the other lone pair is available as H-bond acceptor?). The phenix-specific question involves whether non-bonded interactions will push the atoms apart during refinement, and how to turn off the nonbonded interaction between these two atoms to allow the xray data to determine the position. Under geometry_restraints.edits I define a bond, but give a very large sigma of 1A. Will this effectively remove non-bonded interactions between these two atoms?

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dummy atom v.s. model with zero occupancy.
by Jinzhong Lin 21 Apr '13

21 Apr '13

Dear PHENIX users, In phenix, in order to improve bulk solvent model when the model is not complete, you can add dummy atom and set "refinement.mask.ignore_zero_occupancy_atoms=False". My question is that can I just put a model ( I know the approximate position for the model) there instead of dummy atoms and set all atoms in the model zero occupancy and keep the same setting. Will I get the same result? I suspect that model will still be used to calculate the Fc even though the occupancy is zero, so the map will be severely model biased. Lithlin

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Re: [phenixbb] how to fix a side chain not to be refined?
by Rongjin 20 Apr '13

20 Apr '13

Hi Nat, You are right. By turning off the "fix rotamers" the Arg does not move any more. Best Rongjin ------------------ Original ------------------ From: "Nathaniel Echols"<nechols(a)lbl.gov>; Date: Apr 20, 2013 To: "PHENIX user mailing list"<phenixbb(a)phenix-online.org>; Subject: Re: [phenixbb] how to fix a side chain not to be refined? On Fri, Apr 19, 2013 at 2:14 PM, Rongjin <guanrj(a)foxmail.com> wrote: > I have an Arg with flexible side chain, close to an iodide ion. Every time > I refine it, the side chain of Arg will push the iodide ion away, even I > selected The syntax below looks correct to me, although you should probably do the same thing for the ADP selection, but it's a little disturbing that it's doing this. Do you have rotamer correction turned on? That may be the problem, if it is trying to fit to the difference density (I don't think it's very aware of nearby atoms). -Nat > the Arg not to be refined: > > refine { > strategy = *individual_sites individual_sites_real_space rigid_body \ > *individual_adp group_adp tls *occupancies group_anomalous > sites { > individual = "not (chain A and resid 40)" > } > } > > > The residue 40 in Chain A is that Arg close to the Iodide. Is this selection > correct? > How to fix the side chain of Arg in refinement? > > I attached two pictures, one before and one after refinement, the local area > of the Arg > and the iodide. The iodide is bound to an Asn residue of one symmetric > molecule. > > Thank you > Rongjin Guan > > > > _______________________________________________ > phenixbb mailing list > phenixbb(a)phenix-online.org > http://phenix-online.org/mailman/listinfo/phenixbb > _______________________________________________ phenixbb mailing list phenixbb(a)phenix-online.org http://phenix-online.org/mailman/listinfo/phenixbb .

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how to fix a side chain not to be refined?
by Rongjin 19 Apr '13

19 Apr '13

Hello I have an Arg with flexible side chain, close to an iodide ion. Every time I refine it, the side chain of Arg will push the iodide ion away, even I selected the Arg not to be refined: refine { strategy = *individual_sites individual_sites_real_space rigid_body \ *individual_adp group_adp tls *occupancies group_anomalous sites { individual = "not (chain A and resid 40)" } } The residue 40 in Chain A is that Arg close to the Iodide. Is this selection correct? How to fix the side chain of Arg in refinement? I attached two pictures, one before and one after refinement, the local area of the Arg and the iodide. The iodide is bound to an Asn residue of one symmetric molecule. Thank you Rongjin Guan

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Unusually low B factors
by Brennan Bonnet 17 Apr '13

17 Apr '13

Hi all, I have produced xenon derivatives for SAD phasing of several standard proteins by placing them under xenon gas pressure and then immediately flash freezing in liquid nitrogen. Everything has worked out nicely as far as successful phasing, nice models, and low R factors. Now I've noticed that the B values have decreased from initial processing values. Several rounds of manual changes and phenix.refine have caused B values to decrease each round of refinement to values of around 10 (I guess 20 is a more common value). Does anyone know why this is happening or what the explanation might be? I'm not sure what other information to include so please contact to discuss further. Thanks! ~Brennan

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Exclude atoms from refinements
by Simon Kolstoe 16 Apr '13

16 Apr '13

Hi, I want to exclude some atoms from refinement altogether in phenix.refine. Googling this I came up with the following link: http://phenix-online.org/pipermail/phenixbb/2011-December/018020.html however was wondering how you implement this sort of thing in the GUI? Thanks, Simon --------------------------------------------------------------- Dr. Simon Kolstoe Honorary Senior Research Associate Laboratory for Protein Crystallography Wolfson Drug Discovery Unit University College London Rowland Hill Street, London, NW3 2PF http://www.ucl.ac.uk/~rmhasek ---------------------------------------------------------------

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