April 2008 - phenixbb - phenix-online.org

"unlimit" command with Phenix GUI -unlimit: descriptors: Can't remove limit (Invalid argument)
by hari jayaram 04 Apr '08

04 Apr '08

Hi I am giving new to Phenix and the Phenix GUI. For starters I am trying to run the prime and switch strategy in Phenix. I know all my inputs are fine (see below) but the program aborts ( GUI turns red ) after a few seconds. I checked the resolve.com file in the directory and it has a command "unlimit" which in Leopard causes the following output to be echoed to the stdout "unlimit: descriptors: Can't remove limit (Invalid argument)" Once I deleted the unlimit command I can run the script just fine from a shell. My question is how can I tweak the Phenix GUI so that I dont have to run everything from the shell by manually editing the resolve.com file. The script that stops the GUI is reproduced here. Thanks for your help Hari Jayaram Postdoc , Brandeis University script: #!/bin/csh setenv SOLVEDIR /usr/local/phenix-1.3b-rc6/solve_resolve/ext_ref_files setenv SOLVEBIN /usr/local/phenix-1.3b-rc6/build/mac-intel-osx/solve_resolve/exe # setenv CCP4_OPEN UNKNOWN setenv SYMOP $SOLVEDIR/symop.lib unlimit # $SOLVEBIN/resolve<<EOF access_file mirima.dat labin FP=F_s3-3 FC=FC PHIC=PHIC FOM=FOM FWT=FWT hklin resolve_input.mtz mask_cycles 5 minor_cycles 10 hklout testpms-resolve.mtz no_build prime_and_switch EOF unlimit returns------------> [mango:hj/s3-3/prime_switch] hari% unlimit unlimit: descriptors: Can't remove limit (Invalid argument)

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Crystallographic Postdoctoral Research Position - Berkeley, USA
by Paul Adams 02 Apr '08

02 Apr '08

A postdoctoral research position is available immediately to work on challenging problems in structural biology: Postdoctoral Researcher Job ID: 21615 Division: Physical Biosciences Date Opened: 3/28/2008 This postdoctoral position will study the structure and function of macromolecular complexes and enzymes using X-ray crystallographic methods. This position will be joint between the Center for Protein Folding Machinery (proteinfoldingcenter.org) and the Joint BioEnergy Institute (www.jbei.org). The biological systems to be studied will include: Type-II chaperonins responsible for the refolding of unfolded proteins in archeal and mammalian cells, Glycosyl transferases responsible for the synthesis of hemicellulose in plants, and Novel glycosyl hydrolases that are able to breakdown cellulosic material for biofuels production. The candidate will have experience with using crystallographic methods to study macromolecules; robotic hardware for performing crystallization trials and imaging trays are available. Crystals will be characterized and data collected using the beamline resources of the Berkeley Center for Structural Biology at the Advanced Light Source. Essential: Primary duties and responsibilities will include using robotic hardware to perform screens for crystallization conditions. Optimization of crystallization conditions. Biophysical characterization of protein samples using standard techniques, such as dynamic light scattering. Characterization of crystals using the Berkeley Center for Structural Biology beamlines at the Advanced Light Source. Collection and analysis of diffraction data, model building and structure refinement. Extensive email and verbal interaction with other researchers. Marginal: Use of small angle X-ray scattering methods to analyze macromolecular complexes in solution. Essential: Ph.D. or equivalent in a scientific discipline, preferably structural biology, biology, or chemistry. Demonstrated experience of scientific research using crystallographic methods. Experience with crystallization methods. Solid interpersonal skills and the ability to work in a team environment are critical. Ability to communicate with a broad range of researchers. Marginal: Experience with the use of small angle scattering methods. Familiarity with robotic hardware for crystal growth. NOTE: This is a one year Term appointment with the possibility of renewal under the same terms and conditions, contingent upon continued funding and availability of work. Lawrence Berkeley National Laboratory is a world leader in science and engineering research, with 11 Nobel Prize recipients over the past 75 years, and 59 present members of the National Academy of Sciences. LBNL conducts unclassified research across a wide range of scientific disciplines and hosts four national user facilities. AA/ EEO employer committed to the development of a safe and diverse workforce. Learn more at http://www.lbl.gov. For more information about the Center for Protein Folding Machinery visit: http://proteinfoldingcenter.org/ and the Joint BioEnergy Institute visit: http://www.jbei.org/. For more information about the Berkeley Center for Structural Biology visit: http://bcsb.lbl.gov/ To apply: visit http://cjo.lbl.gov/ and search for the job number 21615. Please see http://cjo.lbl.gov/app_instr.html for details of how to apply. -- Paul Adams Deputy Division Director, Physical Biosciences Division, Lawrence Berkeley Lab Adjunct Professor, Department of Bioengineering, U.C. Berkeley Vice President for Technology, the Joint BioEnergy Institute Head, Berkeley Center for Structural Biology Building 64, Room 248 Tel: 510-486-4225, Fax: 510-486-5909 http://cci.lbl.gov/paul Lawrence Berkeley Laboratory 1 Cyclotron Road BLDG 64R0121 Berkeley, CA 94720, USA. --

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TLS, B factors, phenix and refmac
by Mischa Machius 02 Apr '08

02 Apr '08

Hi - Prompted by the recent discussions on B values, TLS refinement and differences between Phenix and refmac, we looked into these matters in more detail. We found that the crux of the problem lies in the fact that TLS and B value refinements are usually decoupled. We have developed a formalism that rolls both TLS and B value refinement into one. Phenix and refmac were modified to carry out the calculations, and the outputs from both programs were made compatible to allow proper comparison of the results. We found that the stability of the refinements is now vastly improved. More importantly, however, due to the reduced number of parameters, these calculations can be carried out to resolutions of 7 Å with meaningful representations of indiviual, anisotropic atomic displacement parameters. This low-resolution limit required reformulating the calculation of Wilson B values, but that is only a minor aspect of our treatment that can be neglected. The new, combined procedure for the simultaneous refinement of TLS/B is called 'TBS' refinement, reflecting all required components: Translation, Bibation, Screw. Interestingly, the ‘T’ component is fairly insensitive to input parameters, whereas the overall quality of the refinement is greatly dependent on the ‘B’ component. The more emphasis is put on ‘B’, the more convincing the results. There is a limit, though. At very high levels of ‘B’, the so-called ‘bibacity limit’, the refinement becomes very unstable, leading to inversion in severe cases. Seasoned crystallographers familiar with the concepts can successfully push the procedure to quite high 'B limits', whereas less experienced practitioners should follow the protocols very carefully. Please contact us for any details. Best - MM -------------------------------------------------------------------------------- Mischa Machius, PhD Associate Professor UT Southwestern Medical Center at Dallas 5323 Harry Hines Blvd.; ND10.214A Dallas, TX 75390-8816; U.S.A. Tel: +1 214 645 6381 Fax: +1 214 645 6353

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Question about anisotropic refinement of selected waters during automatic solvent update
by Schubert, Carsten [PRDUS] 02 Apr '08

02 Apr '08

Hi, I am trying to refine a couple of waters in a structure anisotropically in the latest version of CCI-Apps (Feb-08) . The selection is: refine.adp.anisotropic = "chain W and (resid 25 or resid 54)" The refinement works fine if "main.ordered_solvent = False". When I enable "main.ordered_solvent" the refinement fails with: "Sorry: Bad (empty or mixed) selection in adp_individual.aniso" during the first update of the solvent in macrocycle 1. A workaround is easy to implement, but I think this kind of scheme should work. Although it has all kinds of tricky implication for the downstream handling of the selection if the residues/waters in questions are deleted.... Cheers, Carsten

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gnomebreakpad error
by shivesh kumar 02 Apr '08

02 Apr '08

Dear all, We are trying to install phenix in Fedora Core 8.While installing it is showing the following error- Gtk-Message: Failed to load module "gnomebreakpad": libgnomebreakpad.so: cannot open shared object file: No such file or directory Please suggest what is wrong or missing. Thanx in advance. Shivesh

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tls definitions
by PhilEvans 02 Apr '08

02 Apr '08

Sorry if this has been answered before, but I've only just joined this BB In phenix.refine, I'm trying to make TLS groups consisting of multiple chains, eg refinement.refine { strategy=individual_sites+tls+individual_adp adp { tls="chain A and chain B and chain Z" tls="chain C and chain D and chain Y" } } but it doesn't work: what should I do? Phil ================== Extract refinement strategy and selections ================= individual_sites = True rigid_body = False individual_adp = True group_adp = False tls = True individual_occupancies = False group_occupancies = False group_anomalous = False size = 1356 n_use = 1356 n_use_u_iso = 1356 n_use_u_aniso = 0 n_grad_site = 0 n_grad_u_iso = 0 n_grad_u_aniso = 0 n_grad_occupancy = 0 n_grad_fp = 0 n_grad_fdp = 0 n_anisotropic_flag = 0 total number of scatterers = 1356 Sorry: Empty selection in adp_tls selection.

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