- phenixbb - phenix-online.org

Re: [phenixbb] Two versions of TFZ, molecular replacement
by yzhao 14 Sep '12

14 Sep '12

Hi, Some information may be needed. The model used to do molecular replacement is not an original homolog PDB file. I feed the homolog structure and sequence alignment to MR_rosetta, and I obtained an overall_best.pdb from AutoBuild(diffraction resolution is about 3. 5A). So I use this overall_best.pdb to run Phaser, and achieved a solution as I just mentioned. the overall_best.pdb from AutoBuild has no obvious regular secondary structure relative to the homolog structure, but their overall appearances are very similar. Before I run Phaser, I also checked native Patterson, there is no large off- origin peak. Additionally, the self rotation function and matthews_coef indicate there is a monomer in ASU. Thanks a lot! -- Yan Zhao Randy Read 写:Hi, There's an explanation of the TFZ== entry and how to interpret the job history on our web page:http://www.phaser.cimr.cam.ac.uk/index.php/ Molecular_Replacement#Has_Phaser_Solved_It.3F Basically, the TFZ=13.9 means that, in the translation search using the orientation that came from the rotation function, the Z-score of this peak was 13.9. However, we found that the TFZ was too sensitive to random errors in the orientation, so Phaser now computes what the TFZ score would have been if the orientation in the translation search had been the optimised one from the rigid- body refinement. (We call this the TFZ-equivalent, denoted as TFZ==.) So after the refinement (giving LLG=235), a random sampling of translations shows that the TFZ score would have been 5.0 for the refined orientation. The next two entries are the LLG after the final refinement at full resolution (239) and the TFZ score for that refined solution (again 5.0). What you see is very unusual behaviour. The TFZ -equivalent is almost always higher than the original TFZ, and I can't recall a case where it was significantly lower. One possible explanation occurs to me. If your crystal has translational NCS ( indicated by a large off-origin peak in the native Patterson) and you're searching for a dimer, a translation search with the dimer axis parallel to a crystallographic 2-fold would give a very sudden increase in the LLG when the dimer is in the right place relative to the crystallographic 2-fold to generate a model that obeys the translational NCS. Then, if the refinement changed the orientation of the dimer so that its axis was less parallel to the crystallographic 2-fold, that would reduce the modulation of the calculated data and reduce the TFZ. If these are the circumstances of your job, then you should be able to fix it by making sure that you have a recent version of Phenix, then running a job looking for 2 copies of the monomer. In that case, Phaser will take proper account of the translational NCS and there won't be any strange artefacts. If those aren't the circumstances, then I'm very puzzled and would appreciate receiving the data, model and other information needed to reproduce your job ( off-line) to check out what is going on! Best wishes, Randy Read On 14 Sep 2012, at 20:13, 赵岩 wrote:Hi everyone, I am trying to solve a structure though molecular replacement and I have obtained a suspected solution. The header of the solution as follows, REMARK TITLE [no title set] REMARK Log-Likelihood Gain: 238.884 REMARK RFZ=10.9 TFZ=13.9 PAK=2 LLG=235 TFZ==5.0 LLG=239 TFZ==5.0 REMARK ENSEMBLE 1 EULER 15.53 0.10 344.54 FRAC -0.499 -1.000 -0.499 At first sight, the solution has no problem(TFZ>8), but the second and third TFZ are very low. For a correct solution, the later TFZs always higher than the first TFZ. So I don't konw how to understand the later TFZs and what extent I can refer to them. Thanks a lot! -- _______________________________________________ phenixbb mailing list phenixbb(a)phenix-online.org http://phenix-online.org/mailman/listinfo/phenixbb ------Randy J. ReadDepartment of Haematology, University of CambridgeCambridge Institute for Medical Research Tel: + 44 1223 336500Wellcome Trust/MRC Building Fax: + 44 1223 336827Hills Road E-mail: rjr27(a)cam.ac.ukCambridge CB2 0XY, U.K. www-structmed.cimr.cam.ac.uk

2 1

Anisotropic scale matrix in phenix.refine
by Alex Taylor 12 Sep '12

12 Sep '12

2 1

Ligand geometry, Ideal vs. Observed
by Yuri 12 Sep '12

12 Sep '12

Hi everyone, I am trying to show that a ligand underwent catalysis during a soaking experiment. One of the things I would like to show is the geometry of the ligand, bond angles/lengths, dihedrals, etc... One of my models has a hi-res of 1.18A and the ligand density is really clear and complete. What is the best way to refine the ligand unrestrained and then generate measurements? Also, the idea is to finally compare to ideal geometry. How should I generate these values (any softwares in mind)? ANy idea is welcome. Thanks a lot -- Yuri Pompeu

2 1

Bond/Angle restraints for multiple copies of ligands/cofactors
by Eckhard Hofmann 11 Sep '12

11 Sep '12

Hi all, if the xray data reach real atomic resolution (say <1A), one can nicely refine cofactors w/o restraints. In intermediate cases, the existence of multiple copies allows to use the "SAME" option in SHELX refinement to restrain identical molecules to each other, somewhat like NCS, but on bonds and angles. Is there a possibility to do something similar with PHENIX? I have structures with up to 16 or more copies in the ASU (and several copies per chain), and 1.1A resolution. This would give me a very stable way to access unbiased information about stereochemistry. (Using NCS is of course not an powerful idea, as the torsion angles might vary between the different copies). Thanks for feedback, Eckhard -- Eckhard Hofmann <eckhard.hofmann(a)bph.ruhr-uni-bochum.de> Ruhr-Uni Bochum AG Proteinkristallographie, LS Biophysik, ND04/316 44780 Bochum Tel: +49-(0)234/32-24463, Sekr. -24461, FAX: -14762

2 1

Advice on final refinement of twinned R3 structure: DETWIN and ML-target vs twin_lsq_sq target
by Bjørn Panyella Pedersen 10 Sep '12

10 Sep '12

Dear list I would like some advice on how to do the final refinement of a twinned structure: I have a 3.0A structure (sg R3) which is twinned. I have collected ~50 datasets and the estimated twin-fraction varies from 0.2 to 0.45 based on phenix.xtriage analysis (britton plot etc). The structure could only be solved by experimental phasing using _detwinned_ datasets (detwinned by the ccp4 program DETWIN). Refinement of the model was initially done using my highest resolution _detwinned_ dataset (3.0A, britton_alpha:0.21) and a ML target in phenix.refine. Lately I have switched to th twin_lsq_f target and refined using the 'unmodified'/twinned dataset. 1. I have tried systematically to detwin the dataset with different twin-fractions and then refine using the ML-target and my best refinements comes using an alpha of 0.2 (see attached figure). This fits the Britton plot etc. 2. xtriage estimated the twin-fraction to by ~0.21, but using twin_lsq_f, phenix.refine now gets alpha to be 0.31. This seems like a large increase to me? 3. Using the manually detwinned dataset and a ML-target gives better R-factors than using the twin_lsq_f target (see attached figure). Bottom line: How should I report/deposit this structure: A. Should I use the manually detwinned data and an ML-target to get a model that explains the data best (lowest R-factors). And deposit my structure with modified (i.e DETWINNED) structure factors. I fear that people would react strongly to the deposition of modified F_obs in the pdb. I could deposit both twinned and detwinned structure-factores but this might also confuse? OR B. Should I use the twin_lsq_f target and accept that my deposited model is not as good as I know it could be. And deposit my structure with the real (i.e TWINNED) structure factors. OR C. Something I'm not aware of means that refinement using the ML-target is not allowed on detwinned datasets, causing me to have artificially low R-factors. I hope I'm not missing something basic here.:) Thank for any advice, pointers and ideas! -Bjørn -- Bjørn Panyella Pedersen, PhD Macromolecular Structure Group Dept. of Biochemistry and Biophysics University of California, San Francisco MC2240, 600 - 16th Street S414 San Francisco, CA 94158-2517 Phone: +1 415-476-3937 E-mail: bjopp(a)msg.ucsf.edu http://www.msg.ucsf.edu

2 1

error message on dev-1145 during den session
by fulvio saccoccia 07 Sep '12

07 Sep '12

Dear Phenix users, here you have an error occurred during a DEN refinement cycle on a twinned structure. Please, help me in order to overcome the problem. This is the command line I used to run phenix: phenix.den_refine data.mtz model.pdb twin_law=h,-k,-l output.prefix=DEN10 --overwrite main.ncs=true set_b_iso=50 convert_to_isotropic=true xray_data.high_resolution=3.6 nproc=4 secondary_structure_restraints=true optimize_xyz_weight=true optimize_adp_weight=true reference_model.file=3ZVJ-coot1.pdb use_geometry_restraints=true den.params fix_rotamers=true den.params is attached I was running phenix dev-1145 on a 64bit Debian machine. This is the error message: Running DEN torsion optimization on 4 processors... Running torsion simulated annealing ...trying gamma 0.0, weight 100.0 ...trying gamma 0.2, weight 100.0 ...trying gamma 0.0, weight 300.0 ...trying gamma 0.2, weight 300.0 Traceback (most recent call last): File "/usr/local/phenix-dev-1145/build/intel-linux-2.6-x86_64/../../phenix/phenix/command_line/den_refine.py", line 21, in <module> den_refine.run(command_name="phenix.den_refine", args=sys.argv[1:]) File "/usr/local/phenix-dev-1145/phenix/phenix/refinement/den_refine.py", line 113, in run customized_master_params=master_phil) File "/usr/local/phenix-dev-1145/phenix/phenix/refinement/command_line.py", line 146, in run call_back_handler=call_back_handler) File "/usr/local/phenix-dev-1145/phenix/phenix/refinement/driver.py", line 1532, in run ncs_manager = self.ncs_manager) File "/usr/local/phenix-dev-1145/phenix/phenix/refinement/strategies.py", line 830, in refinement_machine log=log) File "/usr/local/phenix-dev-1145/cctbx_project/mmtbx/den/refinement.py", line 88, in __init__ "serious error; please contact bugs(a)phenix-online.org.") % so) RuntimeError: DEN weight optimization failed: DEN cycle 1 rfree at start of SA cycle: 0.4642 k_rep = 1.00 tardy_tree summary: number of vertices: 16570 number of edges: 16855 find cluster loops: 0 repeats number of fixed vertex lists: 0 number of fixed vertices: 0 number of clusters: 7857 merge clusters with multiple connections: 1 pass number of hinge edges: 7857 number of loop edges: 0 number of loop edge bendings: 0 number of fixed hinges: 0 CAUGHT EXCEPTION: (argument #0) ARGUMENT LEADING TO EXCEPTION: (0.0, 100.0) Traceback (most recent call last): File "/usr/local/phenix-dev-1145/cctbx_project/libtbx/easy_mp.py", line 155, in __call__ result = O.func(arg) File "/usr/local/phenix-dev-1145/cctbx_project/mmtbx/den/refinement.py", line 227, in try_den_weight_torsion call_back_after_step=False) File "/usr/local/phenix-dev-1145/cctbx_project/mmtbx/refinement/tardy.py", line 228, in run reduced_geo_manager=reduced_geo_manager) File "/usr/local/phenix-dev-1145/cctbx_project/mmtbx/refinement/tardy.py", line 86, in __init__ O.weights = target_weights.xyz_weights_result AttributeError: 'NoneType' object has no attribute 'xyz_weights_result' This is a serious error; please contact bugs(a)phenix-online.org. Thanks in advance Fulvio Saccoccia PhD student Dept. of Biochemical Sciences Sapienza University of Rome +390649910556

2 6

Fwd: mr_rosetta and Condor
by Dmitry Rodionov 07 Sep '12

07 Sep '12

re: > Submitting job(s) > ERROR: No such directory: /Volumes/condor/Sht1/MR_ROSETTA_5/GROUP_OF_PLACE_MODEL_1/"/Volumes/condor/Sht1/MR_ROSETTA_5/GROUP_OF_PLACE_MODEL_1" 1)It appears that the submission problem comes from the Condor job description file: Universe = vanilla Error = err.log Output = out.log Requirements = Memory > 256 copy_to_spool = False Initialdir = "/Volumes/condor/Och1/MR_ROSETTA_32/GROUP_OF_PLACE_MODEL_1" Executable = "/Volumes/condor/Och1/MR_ROSETTA_32/GROUP_OF_PLACE_MODEL_1/RUN_FILE_10.sh" Queue I am able to submit the job manually if i remove the double quotes from initialdir and executable lines. Sounds like a very simple problem. Does anyone know how can this be fixed? 2) shortly after submission, the modified (no quotes) job stops with the following: RUN_FILE_1.log: Rebuilding the model /Volumes/condor/Och1/MR_ROSETTA_32/WORK_1/global_1/2vk9_1_chain.pdb with rosetta ================================================================================ Splitting generation of rebuilt models into 1000 jobs with 1 structures generated per job ================================================================================ ******************* ERROR ENDING *************** 'NoneType' object has no attribute 'endswith' ******************* ERROR ENDING *************** Oddly enough, if I run the script locally it runs without this problem. I understand that the error is Python. Does anybody know where it might be coming from? 2)Another thing is that Condor's err.log and out.log are created in the same location and under the same name for all jobs which "may lead to bizarre behaviour" according to the Condor's manual. Might not be a bad idea to name the files something like run_xx_err.log or stick them into the RUN_xx folder for the sake of safety. Thanks! Dmitry

1 0

restraining covalent links between symmetry related molecules
by Dave Lodowski 06 Sep '12

06 Sep '12

Dear all, I am attempting to add a bond restraint that connects a serine in one molecule to a carbon located in its symmetry mate in the adjacent unit cell. Atom selection 1: chain 'A' and resid ' 230 ' and name ' C ' and altloc 'A' Atom selection 2: chain 'A' and resid ' 179 ' and name ' OG ' and altloc 'A' and (*insert symmetry keyword here*) 'x-1,y,z' (altloc B in both cases is not covalently attached) I cannot seem to find a complete description of the atom selection syntax in the Phenix documentation to specify which symmetry mate. and the gui/ phenix graphics does not have any way to generate symmetry mates. What is the keyword that specifies a symmetry mate? Thanks, Dave Lodowski

2 1

Autosol: MIRAS
by ash.k＠aol.com 06 Sep '12

06 Sep '12

Hi all, I am tryingto solve a structure through experimental phasing using AUTOSOL. I have acouple of heavy atom derivative datasets (Hg, La, Eu, Cd) and also a SeMetdata. Unfortunately all the datasets are of low resolution (3.7-4.2A) and thereare possibly 4-8 molecules in the asu. MIR, SAD and MAD alone did not give any convincing solution. However,MIRAS, with a combination of few heavy atom datasets and the anomalous datafrom SeMet crystals, gave a somewhat satisfactory map. But the heavy atom sitepicked by AUTOSOL list only one of the heavy atoms i.e. Lanthanum. In another set of run, the solution of which was not convincing, the heavy atom substructure had only Hg. There are 6Met out of 200 residues in one molecule and mass spec results show that Seincorporation is 100%. Now, mydoubt is that why does the heavy atom substructure contain only La and how canI get the substructure involving Se from this solution (or the datasets used)? Se location is going to help me a lot forfinding a starting point to assign side chains. Anysuggestion would be greatly appreciated. Thanks AK

4 8

Partially occupied side chains in special position
by Nicholas Keep 05 Sep '12

05 Sep '12

I have an ARG which has nice density for its guanadinium group on a 2 fold. This is the same conformer from the two copies. The occupancy of this chain is set to 0.5 and a second conformer that does not cross the two fold is provided. There is clearly a repulsion term in phenix refines that moves the quanadinium away from the two fold. Do the atoms of the guanadinum group need to have an occupancy of 0.25? Can I specify no repulsion between these symmetry elements? Best wishes Nick -- Prof Nicholas H. Keep Executive Dean of School of Science Professor of Biomolecular Science Crystallography, Institute for Structural and Molecular Biology, Department of Biological Sciences Birkbeck, University of London, Malet Street, Bloomsbury LONDON WC1E 7HX email n.keep(a)mail.cryst.bbk.ac.uk Telephone 020-7631-6852 (Room G54a Office) 020-7631-6800 (Department Office) Fax 020-7631-6803 If you want to access me in person you have to come to the crystallography entrance and ring me or the department office from the internal phone by the door

2 1