- phenixbb - phenix-online.org

Postdoctoral Position for PHENIX development
by Paul D. Adams 02 Aug '07

02 Aug '07

======================================================================= Lawrence Berkeley National Laboratory Computational Postdoctoral Fellow ======================================================================= Computational Postdoctoral Fellow Job ID: 20907 Division: Physical Biosciences Date Opened: 8/2/2007 Summary We are seeking an intelligent, motivated scientist to develop graphical tools for the PHENIX software system. The successful candidate will work under the direction of the Principal Investigator for this project. Primary duties and responsibilities will include development and implementation of graphical interfaces, user workflow tools, and mechanisms for data tracking and storage. Duties Essential - Primary duties and responsibilities will include development and implementation of computational algorithms for structure determination using X-ray crystallography. Develop graphic interfaces to components of the PHENIX software system. Create interfaces between PHENIX and other software packages such as Coot. Implement software code for capturing and tracking data and other information as it is created by the PHENIX software. This position requires interaction with P.I.s, postdocs, Scientists and external collaborators involved in the PHENIX project. Publication of research results in scientific journals and presentation of results at scientific meetings. Marginal - Actively participate in group meetings. Assume shared responsibility for maintenance of computational equipment with other group members. Qualifications Essential - Ph.D. within the last three years in computational crystallography or a related field. Demonstrated experience with graphical interface development. First-author publications in macromolecular crystallography or closely related field. Familiarity with software development tools such as C++, C or Fortran programming languages and scripting languages such as Python or Perl. Strong programming skills. Solid interpersonal skills and the ability to work in a team environment are critical. Marginal - Experience with the practical aspects of protein crystallography: protein production, crystallization and structure solution. 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 PHENIX visit: http://www.phenix-online.org/ For more information about the CCI visit: http://cci.lbl.gov/ To apply: visit http://cjo.lbl.gov/ and search for the job number 20907. Please see http://cjo.lbl.gov/app_instr.html for details of how to apply. -- Paul Adams Senior Scientist, Physical Biosciences Division Head, Berkeley Center for Structural Biology Deputy Principal Investigator, Berkeley Structural Genomics Center Building 64, Room 248 Tel: 510-486-4225, Fax: 510-486-5909 http://cci.lbl.gov/ Lawrence Berkeley Laboratory 1 Cyclotron Road BLDG 64R0121 Berkeley, CA 94720, USA. --

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estimated coordinate error
by Jianghai Zhu 01 Aug '07

01 Aug '07

Hi, I am refining a 2.6 A structure using both phenix.refine and refmac5. Both programs give me similar R and Rfree values. But the estimated coordinate errors are quite different. From phenix.refine: maximum likelihood estimate for coordinate error: 0.42 A From refmac5: estimated overall coordinate error: ESU based on R value: 0.427 A ESU based on Free R value: 0.293 A ESU based on maximum likelihood: 0.239 A I am wondering why they are different. Jianghai +++++++++++++++++++++++++++++++ Jianghai Zhu, Ph.D CBR Institute for Biomedical Research Department of Pathology Harvard Medical School 200 Longwood Ave., Boston, MA 02115 Ph: 617-278-3211 Fx: 618-278-3232 +++++++++++++++++++++++++++++++

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General Question !!!
by john kryst 01 Aug '07

01 Aug '07

Hi all !! Please bare with me.. one general very basic question. Do we use electrostatic charges in x-ray refinement. regards John

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AutoSol problem
by Ben Eisenbraun 31 Jul '07

31 Jul '07

Hi- One of my users is running the Linux 64-bit version of Phenix-1.3b and they are getting the following message at the end of their logfile: ************************************************************ Failed to carry out AutoSol_scale_and_analyze_mad: None of the solve versions worked ************************************************************ The solve part of Phenix looks like it built correctly: $ ls -l phenix-1.3b/build/intel-linux-2.6-x86_64/solve_resolve/exe/ -rwxr-xr-x 1 sbgrid sbgrid 1561344 Jun 27 16:55 extract_segment -rwxr-xr-x 1 sbgrid sbgrid 1561344 Jun 27 16:55 extract_segment_pair -rwxr-xr-x 1 sbgrid sbgrid 3483160 Jun 27 16:55 resolve -rwxr-xr-x 1 sbgrid sbgrid 3483576 Jun 27 16:55 resolve_extra_huge -rwxr-xr-x 1 sbgrid sbgrid 3483256 Jun 27 16:55 resolve_giant -rwxr-xr-x 1 sbgrid sbgrid 3482968 Jun 27 16:55 resolve_huge -rwxr-xr-x 1 sbgrid sbgrid 1768392 Jun 27 16:55 resolve_pattern -rwxr-xr-x 1 sbgrid sbgrid 1768392 Jun 27 16:55 resolve_pattern_extra_huge -rwxr-xr-x 1 sbgrid sbgrid 1768392 Jun 27 16:55 resolve_pattern_giant -rwxr-xr-x 1 sbgrid sbgrid 1768392 Jun 27 16:55 resolve_pattern_huge -rwxr-xr-x 1 sbgrid sbgrid 1547840 Jun 27 16:55 segment_library -rwxr-xr-x 1 sbgrid sbgrid 1575648 Jun 27 16:55 side_chains -rwxr-xr-x 1 sbgrid sbgrid 1566208 Jun 27 16:55 side_chains_update -rwxr-xr-x 1 sbgrid sbgrid 5327984 Jun 27 16:55 solve -rwxr-xr-x 1 sbgrid sbgrid 11331152 Jun 27 16:55 solve_extra_huge -rwxr-xr-x 1 sbgrid sbgrid 6529136 Jun 27 16:55 solve_giant -rwxr-xr-x 1 sbgrid sbgrid 7729424 Jun 27 16:55 solve_huge -rwxr-xr-x 1 sbgrid sbgrid 11393392 Jun 27 16:55 solve_mx $ file phenix-1.3b/build/intel-linux-2.6-x86_64/solve_resolve/exe/solve phenix-1.3b/build/intel-linux-2.6-x86_64/solve_resolve/exe/solve: ELF 64-bit LSB executable, AMD x86-64, version 1 (SYSV), for GNU/Linux 2.4.0, statically linked, for GNU/Linux 2.4.0, stripped We do have a standalone Solve install with its corresponding SOLVEDIR, etc, environment variables. Could that be confusing Phenix? I have the complete logfile, but it's rather long. If it would help, it can be made available. Any ideas on what I should do to troubleshoot this? Thanks. -ben -- Ben Eisenbraun Structural Biology Grid http://sbgrid.org/

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TEST - please ignore
by Luca Jovine 31 Jul '07

31 Jul '07

Sorry, just re-testing whether my e-mails to phenixbb are still vanishing into nowhere...

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A question about AutoBuild
by Marcelo Carlos Sousa 30 Jul '07

30 Jul '07

We have solved (in part) a structure by Molecular Replacement. The protein is a homodimer with 360 amino acids per chain (one dimmer per asu). The model was pretty good for the last 220 amino acids or so but appears to be wrong for the first 140 so I deleted them and refined using phenix to an R free of ~ 0.38. As I was about to start model building in O I thought I would give the phenix autobuild a try. The resolution is 2.5 Å and the map shows buildable features for the missing domain. I ran the autobuild wizard with RESOLVE building “in- place” to extend the current model. However the program seemed unable to add fragments of secondary structure (even as alanines) to the model. The question is: is the building “in-place” restricted to “growing” the current model from the ends? Marcelo

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part II. A question about autobuild
by Marcelo Carlos Sousa 30 Jul '07

30 Jul '07

I also noticed that water molecules are assigned to the buildable parts of the map.

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R-factor problem !!!
by john kryst 30 Jul '07

30 Jul '07

Hi all !! I am using phenix.refine to refine my 3.2 A structure. Also i use xtal_pdbsubmission utility in CNS to generate pdb file which is submission ready format. Please note no refinement in CNS only formating. Phenix.refine gave a R and Rfree of 0.1929 & 0.2512 ( rmsd bonds = 0.006) respectively. When i format in CNS it gave R and Rfree 0.2282 & 0.2794 ( rmsd bonds= 0.010865 ). Am i doing any mistake ?? As for as i know we cant generate a submission ready PDB format from phenix.refine. Is it possible to implement it, which will be very helpful for all of us. Thanks in advance for your inputs regards John

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problems with clashes
by Lari Lehtio 30 Jul '07

30 Jul '07

Hi, I nowadays use phenix.refine almost always in the first stages of the refinement and later usually move to refmac. Now I have two modest resolution structures which behave much better in phenix than in refmac. In addition to the more tedious deposition (I guess), I have a problem with clashes. When I analyse the structures with molprobity, I get much better clashscores with refmac refined files. Is there a way to increase the restraint for these contacts or should I just keep decreasing the wxc_scale (from the default)? Rmsds reported by refmac (0 cycles) for bonds and angles are already lower than what I'm used to. B-factors on the other hand seem to be less restrained in phenix. ~Lari~ _______________________________________ Lari Lehtiö Structural Genomics Consortium Medical Biochemistry & Biophysics Dept. Karolinska Institute Stockholm, Sweden _______________________________________

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Re: [phenixbb] ramachanran plot refinement or restraint?
by Ralf W. Grosse-Kunstleve 27 Jul '07

27 Jul '07

Hi Jianghai, > I tried "discard_psi_phi=False" in phenix.refine. There is only > slightly improvement in the R, Rfree, and ramachandran plot (about > 0.2% less disallowed residues, wxc_scale=0.2). A structure > optimization (wxc_scale=0) with the phi-psi restraints has a bigger > impact (about 2% less disallowed residues) with about 2% higher > Rfree. Thanks for your feedback! > What do you think is a good value for wxc_scale in a low-resolution > refinement? This is a tough one to answer. wxc_scale reflects how much you trust your data to guide you to the best model. That depends on many influences. I think the best - although expensive - approach is to simply try a range of values. Note that the esd on the psi-phi restraints are just someone's (?) best guesses. It may be worth playing with these values as well. For that, copy the data_link_TRANS, data_link_PTRANS, data_link_CIS, and data_link_PCIS blocks from mon_lib_list.cif to a new files, change the values, then specify the file on the phenix.refine command line. (You may want to double-check in the .geo file that your new values are actually used.) > What is the difference between wxc_scale=0 and > phenix.geometry_minimization? Should basically be the same, but in phenix.refine you can override parameters like discard_psi_phi. phenix.geometry_minimization doesn't allow you to do this (it is one of those many little things I never got to). Ralf

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