- phenixbb - phenix-online.org

weights optimization, add hydrogens
by Ursula Schulze-Gahmen 24 Feb '10

24 Feb '10

I am refining a 2.0 A structure in Phenix using mostly the graphical interface. The maps are very good and the R factors are low (0.208/0.173). But the geometry is not so great with bond deviations of 0.208 and Angle deviations of 1.85. What is the best thing to do to try to improve the geometry. Should I try to optimize the weights? The other question is about adding hydrogens to the model. I did add them in a previous refinement cycle. After rebuilding the model in coot, most of the model still has the hydrogens in the input file for the next refinement cycle, but some residues and waters don't have hydrogens. When I tried to add hydrogens again to the model, I got an error message about atoms being to close. Does Phenix know where to add hydrogens if the input model has already hydroegns on many residues? Thanks Ursula -- Ursula Schulze-Gahmen, PhD. QB3, Tjian Lab MCB, 16 Barker Hall #3204 University of California Berkeley Berkeley, CA 94720-3204 Phone: (510) 642 8258 uschulze-gahmen(a)lbl.gov

6 5

Phenix.ligandfit is not happy with my labels
by ucbccka 24 Feb '10

24 Feb '10

I am getting an error when trying to run phenix.ligandfit in the version phenix-1.6-289. I am trying to get it to use an mtz generated via refmac <recoils at the chorus of booooo's> and fit the ligand into the difference map. If I run phenix.ligandfit data=phaser_1.1_refmac1.mtz model=phaser_1.1_refmac1.pdb ligand=ATP.pdb It complains about my labels, saying.. ********************************* Sorry, input labels or map type unclear for phaser_1.1_refmac1.mtz For lig_map_type=pre_calculated_map_coeffs supply F and PHI (optionally FOM) (or 2FOFCWT and PH2FOFCWT) For lig_map_type=fo-fc_difference_map supply one column label for FP For lig_map_type=fobs_map supply one column label for FP Please specify which lig_map_type above you would like and also specify the necessary input column labels for your map like one of these samples: input_labels="FP" input_labels="2FOFCWT PH2FOFCWT" input_labels="FP PHIB FOM" ************************************* Looking at the documentation I tried getting PHENIX to tell me what labels it could see by running that autosol query and it kindly told me that my mtz file contained ************************ 'FreeR_flag' 'F_New' 'SIGF_New' 'FC' 'PHIC' 'FC_ALL' 'PHIC_ALL' 'FWT' 'PHWT' 'DELFWT' 'PHDELWT' 'FOM' ************************** so, I ran phenix.ligandfit data=phaser_1.1_refmac1.mtz model=phaser_1.1_refmac1.pdb ligand=ATP.pdb input_labels="DELFWT PHDELWT" and got the original message complaining that my labels are unclear. I even used the GUI, it recognises all the pairs of labels giving me the options to look at each map if I want and then..... complains that my labels are unclear. Clearly my labels are unclear, but I am now unclear how to proceed. If anyone could suggest something please then I would be most appreciative. Clearly. cheers

3 2

Technology Specialist Position, Lawrence Berkeley National Laboratory
by Paul Adams 23 Feb '10

23 Feb '10

We are seeking a structural biologist technology specialist to research, document, and communicate new technologies to the scientific community. This project is part of the NIH-funded Protein Structure Initiative (PSI) Knowledgebase. The position requires interactions with other groups in the Knowledgebase, members of the Protein Data Bank, researchers at NIH-funded PSI centers, scientific journals, and the broader biological research community. The successful candidate will work under the direction of the Principal Investigator for this project. Primary duties and responsibilities are promoting new PSI- developed technologies to the broader scientific community, and maintaining and further developing a web portal describing these technologies. The successful candidate will need to be able to produce attractive online content, and have good scientific writing /proof reading skills. There is also a large community outreach element to the role, including presentations at meetings, the answering of questions via email, and the possibility of establishing an online forum. Additional tasks may include setting up a SVN software repository, and other online tools which will be of assistance to the structural biology community. Qualifications: B.S., M.S., Ph.D. or equivalent in a scientific discipline, preferably structural biology, biology, or chemistry. Demonstrated experience of scientific research using either computation or instrumentation. Solid interpersonal skills and the ability to work in a team environment are critical. Ability to communicate with a broad range of researchers. Excellent spoken and written English skills are essential. Familiarity with scripting languages such as Python. Experience with maintaining web sites. To apply: visit http://cjo.lbl.gov/ and search for the keyword PSI or the job number 24114. Please see http://cjo.lbl.gov/app_instr.html for details of how to apply. 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. -- Paul Adams Acting 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: 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: Patty Jimenez [ PAJimenez(a)lbl.gov ] [ 1-510-486-7963 ] --

1 0

metal ion
by chene＠umbi.umd.edu 20 Feb '10

20 Feb '10

Dear Phenix users, My question may have been asked before. I am refining a structure containing calcium ions. I am wondering if the program considers it to be divalent Ca++ or neutral calcium atom. It seems that the ion and neutral atom have different atomic scattering factors. Thanks Chen Chen Chen, PhD, Research Associate Center for Advanced Research in Biotechnology (CARB), University of Maryland Biotechnology Institute (UMBI), 9600 Gudelsky Drive, Rockville, MD 20850 240-314-6122

2 1

Re: [phenixbb] riding model and deposition
by Alex Theodossis 19 Feb '10

19 Feb '10

Dear Pavel, thank you for your comments. Alex

1 0

omit map with twinning?
by Kelly Daughtry 18 Feb '10

18 Feb '10

Hello all, The omit_map in the new gui (version 1.5) is great, but I can not include a twin law when calculating the omit map, thus the result is very messy unclear maps. I do not know if 1.6 has the solution or not, I am still lobbying our computer guy to upgrade to it... Is there a way from the command line i can include the twin law in autobuild so I can calculate the omit map, or can I just add it into the eff file? My other solution has been to use the create maps function with my data and pdb with ligand removed. This works, giving me a nice Fo-DFc map, but it would be nice to be able to show a true omit map for the ligand, as is customary in most structure papers I have run across. Thanks in advance for any help you can provide! Kelly ******************************************************* Kelly Daughtry PhD Candidate Department of Physiology and Biophysics Boston University School of Medicine 590 Commonwealth Ave R 390 Boston MA, 02215 (P) 617-358-5548 *******************************************************

4 14

riding model and deposition
by Alex Theodossis 18 Feb '10

18 Feb '10

Dear phenixbb, I have refined a 1.3A structure using individual anisotropic B-factors (Rfactor, 15.5%; Rfree, 17.7%). Additional use of the riding model during refinement has improvement the R values (Rf, 14.5%; Rfree, 16.6%), although bond length and angle outliers did increase (anyone know why that would be?). I have decided to deposit the model obtained using the riding model, but am unsure whether to include the hydrogen coordinates in the deposition. The Phenix.refine documentation advises that they are left in, as they are needed to reproduce the refinement statistics. However, reviewing the high resolution structures in the PDB I found that: 1. In the case of structures refined using REFMAC or SHELX, the riding model does not seem to be included, although its use during refinement is mentioned in the pdb header. 2. In the case of structures refined using PHENIX, use of the riding model is sometimes indicated in the header, but hydrogen coordinates only appear to be included in the pdb in the case of structures refined to a resolution better than 1.3A. As far as I can understand the purpose of the riding model is to provide additional restraints for refinement, so as long as its use is made evident in the pdb header (and maybe the methods section of the publication) that should be enough. Inclusion of hydrogens in the model, when you can't see them seems inappropriate. Nevertheless, I would appreciate a more authoritative perspective on this issue. Thank you in advance, Alex Theodossis

5 7

refinement error with ligand
by Christian Roth 17 Feb '10

17 Feb '10

Dear all, I started a refinement of one of my structures using the GUI of phenix (Version 1.6). I used the options of adding hydrogens and dis a suimulated annealing. I used the output file and corrected it manually using Coot. I incorporated a few Ethylenglycol Monomers which might have bound. I merged everything wrote the file out and loaded this pdb in the GUI. I got an error which might be du to the fact that I didnt specify a CIF file for the ligand. I started ready set from the GUI to check the pdb and used REEL to create a CIF File. I added the CIF-File to the File list and tried to start again phenix.refine using the hydrogen option but no sim. annealing. However I got always the following error log: # Date 2010-02-17 Time 12:00:35 CET +0100 (1266404435.31 s) #phil __OFF__ Command line arguments: "/homes/roth/clcf/049b32mlsyncref/phenix/phenix/project_data/refine_15.eff" "-- overwrite" HOST = bbzws339 HOSTTYPE = i486-linux VENDOR = intel USER = roth PID = 29983 ------------------------------------------------------------------------------- PHENIX: Python-based Hierarchical ENvironment for Integrated Xtallography Version: 1.6 Release tag: 289 Platform: intel-linux-2.6 linux User: roth ------------------------------------------------------------------------------- phenix.refine: Macromolecular Structure Refinement Monomer Library directory: "/software/linuxsoft/phenix-1.6-289/chem_data/mon_lib" Total number of atoms: 16881 Number of models: 1 Model: "" Number of chains: 19 Chain: "A" Number of atoms: 1575 Number of conformers: 1 Conformer: "" Number of residues, atoms: 94, 1575 Classifications: {'peptide': 94} Modifications used: {'COO': 1, 'NH3': 1} Link IDs: {'PTRANS': 6, 'TRANS': 87} and so on for other chains Chain: "R" Number of atoms: 7 Number of conformers: 1 Conformer: "" Number of residues, atoms: 1, 7 Unusual residues: {'EDO': 1} Unexpected atoms: {'EDO,HO1': 1, 'EDO,HO2': 1} Classifications: {'undetermined': 1} Number of atoms with unknown nonbonded energy type symbols: 16 "HETATM16821 HO2 EDO K 1 .*. H " "HETATM16826 HO1 EDO K 1 .*. H " "HETATM16828 HO2 EDO L 1 .*. H " "HETATM16834 HO1 EDO L 1 .*. H " "HETATM16836 HO2 EDO M 1 .*. H " "HETATM16840 HO1 EDO M 1 .*. H " "HETATM16842 HO2 EDO N 1 .*. H " "HETATM16848 HO1 EDO N 1 .*. H " "HETATM16850 HO2 EDO O 1 .*. H " "HETATM16857 HO1 EDO O 1 .*. H " ... (remaining 6 not shown) I looked in the pdb for this atoms, but I cannot find them. When I use a cif file created directly by phenix elbow using command line and when I did not use the update hydrogen button the refinement works. But the new residues as well as the EDO molecules have no hydrogens in riding positions. Do I have to remove all hydrogens and attach them again for every cycle? One Refinement runs for more then 5 hours regardless I use sim annealing or not. This seems to be very long for me. Maybe I want too many optimization steps? Could anyone explain me what goes wrong here. I am no so much experienced with phenix and now I run out of ideas. Thanks in advance Christian

4 4

phenix.elbow and compound refinement
by YS. Chung 16 Feb '10

16 Feb '10

Dear all, I am having some difficulties in refining my compound within my structure. I was able to create the compound and the cif file using PRODRG and was able to fit it in coot perfectly fine. However, as pointed out by many users of phenix.refine, the cif file from PRODRG does not work well with phenix.refine. I have created a cif file using phenix.elbow and the refinement itself works fine. However, when I try to use the cif file from phenix elbow in coot, it pulls apart my compound and it's extremely difficult to work with. This still happens when I create the cif file using the --final_geometry option. Is there a way around this or is there something I can do? Any help will be much appreciated. Thank you, Yu Seon Chung

2 1

refinement at 4.4 A => side chains or not
by jonathan elegheert 12 Feb '10

12 Feb '10

Dear bb, could anyone please share his/her opinion on following matter; I am refining a 4.4 A protein complex structure which I could solve using MR with the high resolution models of the separate components. I also have another 3.5 A crystal form of the complex. My question is whether or not to rebuild/leave "positionally known" side chains in the 4.4 A structure, because of course 2/3 of the time there is of course no density for it. However, a review of the PDB learnes that almost all models deposited between 4 and 5 A contain full side chains! Personally my opinion is not to include them because a model should be a representation of the information content of the experiment and thus density, but maybe that deviates from the consensus. On a more technical note: until now the trimming procedure has only sporadically led to Fo-Fc 'blobs' in the hydrophobic protein interior; are there proven modifications one has to apply to the bulk solvent model mask to avoid these even more? Thanks a lot for your insights, Jonathan -- Jonathan Elegheert Ph.D. Student Unit for Structural Biology& Biophysics http://www.lprobe.ugent.be/xray.html Lab for Protein Biochemistry and Biomolecular Engineering Department of Biochemistry& Microbiology Ghent University, Belgium e-mail: jonathan.elegheert(a)ugent.be

3 2