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rotamer outlier reduction by coot
by Dialing Pretty 05 Dec '11

05 Dec '11

Dear All, I am leaning rotamer outlier reduction by Coot. After select a rotamer and acception, I find some hydrogens in the outlier rotamer will be isolated from the rotamer, and the rotamer will have new hydrogens at its new position. Is any influence by further refine by phenix? After new rotamer acception, I have did the rotamer auto-fit, I find there is a trend on that several oxygens can pack together. How to process this problem? After I save the new PDB file by coot after I selected the new rotamers to replace the outlier rotamers, I did a Phenix refine. There is an error message at the start says "Number of atoms with unknown nonbonded energy typensymbol: 2228". What does it mean and how to solve the problem? Is any simple method by which I can do the rotamer outlier reduction by Coot? I am looking forward to getting your reply. Dialing

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documents explaining parameter settings in phenix-1.7.2
by Ruan Wenjie 05 Dec '11

05 Dec '11

Hi, I want to know, about the new Phenix-1.7.2 version, whether I can find some detailed documents explaining how to set the parameters..since there are so many options and I'm not clear their meaning..Thanks~ best, wenjie

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Job Opportunity - Head of the Berkeley Center for Structural Biology
by Paul Adams 04 Dec '11

04 Dec '11

The Physical Biosciences Division at Lawrence Berkeley National Laboratory is seeking candidates for the Head of the Berkeley Center for Structural Biology. This position provides scientific, technical and operational oversight of the BCSB at the Advanced Light Source (ALS), a third generation synchrotron facility. The BCSB is a user resource for structural biology experiments and consists of 5 beamlines at 2 sectors of the ALS, with a staff of 16. This Staff Scientist position will provide leadership and direction to develop methodology and instrumentation for collecting and analyzing crystallographic data using synchrotron radiation, and on projects involving the structure determination of biological molecules using X-ray crystallography. This position focuses on the field of crystallography, and involves interactions and collaborations with researchers from multiple scientific disciplines including chemistry, crystallography, biochemistry, biology, physics and computational sciences. For full details please visit the job application link at: https://lbl.taleo.net/careersection/2/jobdetail.ftl?lang=en&job=73970 Lawrence Berkeley National Laboratory is a world leader in science and engineering research, with 13 Nobel Prize recipients over the past 75 years. 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 about the Lab at http://www.lbl.gov. -- Paul Adams Deputy Division Director, Physical Biosciences Division, Lawrence Berkeley Lab Division Deputy for Biosciences, Advanced Light Source, Lawrence Berkeley Lab Adjunct Professor, Department of Bioengineering, U.C. Berkeley Vice President for Technology, the Joint BioEnergy Institute Laboratory Research Manager, ENIGMA Science Focus Area Building 64, Room 248 Tel: 1-510-486-4225, Fax: 1-510-486-5909 http://cci.lbl.gov/paul Lawrence Berkeley Laboratory 1 Cyclotron Road BLDG 64R0121 Berkeley, CA 94720, USA. Executive Assistant: Louise Benvenue [ LBenvenue(a)lbl.gov ][ 1-510-495-2506 ] --

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pdb hierarchy
by Bradley Hintze 04 Dec '11

04 Dec '11

Hi Phenix, I have a hierarchy question. I was using the hierarchy and got something that I did not expect. when running this: pdb_io = pdb.input(pdbfile) hierarchy = pdb_io.construct_hierarchy() for model in hierarchy.models(): print model.id for chain in model.chains(): print ' ' + chain.id When I do this I expect the chains in pdbfile to be printed once for each model in pdbfile. However, when I ran this I got, for example, chain 'A' printed four times under the same model. Why is this? Thanks, Bradley

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Writing PDB
by Bradley Hintze 04 Dec '11

04 Dec '11

Hi again, I am trying to take a pdb and write out a new pdb with just a specified chain. I am trying to do this with the hierarchy but am unfamiliar with its functions How do I do this? Thanks, Bradley

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the Ming dial
by Dialing Pretty 04 Dec '11

04 Dec '11

Dear All, In the Ming dial, there is a occupancy (%), which indication of excellent , good, etc. Does it mean if I choose the "occupancy" of excellent, the rotamer outlier ratio will be lowered? My crystal has a resolution of 2.8, and I find no matter how I turn the dial, the original fits the map best. Currently my rotamer outlier is 8%, thus I need the way to have it solved. In addition, for Coot and Ming, which is much convenient to reduce rotamer outlier? I am looking forward to getting your reply. Cheers, Fenghui

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on the rotamer optimization
by Dialing Pretty 03 Dec '11

03 Dec '11

Dear All, Besides Coot and Ming, is any software or server which could further optimize the side chain outliers? I am looking forward to getting your reply. Cheers, Dialing

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solvent model in phenix.refine
by Weiergräber, Oliver H. 01 Dec '11

01 Dec '11

Hello, the ordered_solvent option in phenix.refine apparently uses these parameters by default: min_model_peak_dist = 1.8 max_model_peak_dist = 6.0 min_peak_peak_dist = 1.8 I was wondering about the justification for this (extremely relaxed) set of limits. As far as I know, the shortest hydrogen bonds (if defined as donor-acceptor distance) are about 2 A, and even these are considered exceptional and rare. Similarly, anything in excess of 3.5 A is quite unlikely to be significant energetically, so why use 6 A as an upper limit? Even if max_model_peak_dist was only meant to limit the extent of the outer solvent shell, there is no such thing as max_peak_peak_dist to avoid unreasonably long individual bonds. My personal suggestion would be a range of about 2.3 - 3.2 A for a significant hydrogen bond, with the lower limit exemplified by charged interactions (carboxyl-water or oxonium-water), which tend to be shorter - and stronger - than average. On the other hand, I do frequently observe elongated densities which, in accordance with the default parameters, are typically interpreted by phenix.refine as two water molecules about 2 A apart. So the question arises whether this is a realistic assumption, compared to a "sliding water" model in which the position of a single molecule is just ill-defined in a certain direction (due to a competition of adjacent binding sites for example)? Best regards, Oliver ================================================ PD Dr. Oliver H. Weiergräber Institute of Complex Systems ICS-6: Structural Biochemistry Tel.: +49 2461 61-2028 Fax: +49 2461 61-1448 ================================================ ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDirig Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Karsten Beneke (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------

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Clashing alternative conformations
by Sozanne Solmaz 01 Dec '11

01 Dec '11

Dear all, I have the following problem: I have a homodimer of two protein chains A and B, which I refine in Phenix, and one residue has 2 alternate conformations (a and b) for each chain. If the residues of both chains A and B are in the alternative conformation b, they clash. However, I would expect that never both residues are in conformation b, and therefore only the combinations aa, ab and ba of alternative conformations exist. My problem is, that during the refinement, the two b conformations of the residues clash, which drives the clash-score of the overall structure to a very high value and repulsion pushes the two b-conformations apart during refinement, therefore I cannot model them properly. Is it possible in Phenix to define these two conformations as non-clashing and non-repulsive? Thank you, best regards, Sozanne Solmaz.

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"nproc" in phenix.refine
by Jonathan Elegheert 30 Nov '11

30 Nov '11

Dear all, I have a question regarding the "nproc" parameter in phenix.refine; We have the software installed on our university HPC cluster, which has nodes built up of 8 processors each. Submission works via a queuing system ("qsub"). I understand that compiling with OpenMP renders the nproc parameter disfunctional. Does this then imply that I will be limited to 1 node (8 processors) if compiled without OpenMP, since there is no "message passing" to other nodes? Or is there a way to make use of more of the available nodes, for example by compiling with OpenMP and then specifying many nodes with 1 processor? Best regards, Jonathan Elegheert PhD Student Unit for Structural Biology & Biophysics Ghent University jonathan.elegheert(a)ugent.be

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