- phenixbb - phenix-online.org

Phasing using CryoEM Map
by Alexander Kintzer 02 Sep '14

02 Sep '14

Hello All, I trying to phase my 4Å data with low resolution cryoEM maps (various 12-18Å). There is some documentation, but not really for dealing with EM data. I am having trouble converting the EM data from mrc to suitable F's for phaser. One would want to try different density contours of the cryoEM map, but I haven't found a good way to accomplish this. I also have been unable to search for Ta6Br12 clusters using Autosol even though the documentation seems to suggest that it is possible using the "TX" or "XX" designation for heavy atom search. Any guidance would be extremely helpful. best, Alex

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Tau angles
by George Devaniranjan 02 Sep '14

02 Sep '14

Hi, Is there a way of extracting the tau (and omega) angles of residues in phenix ? Thank you

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Re: [phenixbb] following on the anomalous map
by Kay Diederichs 29 Aug '14

29 Aug '14

Hi Charles, > Date: Thu, 28 Aug 2014 09:59:30 -0400 > From: CPMAS Chen <cpmasmit(a)gmail.com> > To: Gabor Bunkoczi <gb360(a)cam.ac.uk> > Cc: "PHENIX user mailing list \(phenixbb(a)phenix-online.org\)" > <phenixbb(a)phenix-online.org> > Subject: Re: [phenixbb] following on the anomalous map > Message-ID: > <CAAU4GKbzA37j=51X4jMOJjq3t4rKW7Jz9+CQrPxO-HN1kFOOiQ(a)mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > HI, Gabor, > > Thanks for you suggestion. > > I tried this method, it did not give out NO sites for Br. > > why there is apparent anomalous signal and I cannot identify any Br sites? are you sure that your data processing used the correct parameters? E.g. in XDS you should definitively be using "FRIEDEL'S_LAW=FALSE". If you use XSCALE after XDS, it automagically picks up this setting from XDS_ASCII.HKL i.e. you don't have to specify this again. If you, by mistake, use FRIEDEL'S_LAW=TRUE, then the large intensity differences of Friedel pairs will be judged as outliers by XDS, and these reflections will be rejected - that might lead to featureless maps. If the anomalous signal is very strong, and the multiplicity is high, and the Chi^2 values are >1.5, you may also want to use (additionally) "STRICT_ABSORPTION_CORRECTION=TRUE" . But this is rarely necessary. There are similar options in other data processing programs. If you mix and match data processing programs (e.g. XDS integration and aimless scaling) you have to be careful to have the right settings in all programs. best, Kay > > As Nat pointed out, other atoms should have very weak anomalous signal > diffracted at Br absorption peak (3.8e- for Br, versus 0.2e- for the > sulfurs). In the difference map, I can clearly see some peaks at high sigma > (> 6), but the anomalous difference map(they are all generated by > phenix.refine or phenix.maps) is almost featureless, or the peaks has > no overlaps. The anomalous difference gives the possible place of Br while > the difference map gives the possible place of the whole ligand, and I > assume there should be some overlaps between them. Am I right? > > Charles >

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Re: [phenixbb] following on the anomalous map
by CPMAS Chen 29 Aug '14

29 Aug '14

HI, Gabor, Thanks for you suggestion. I tried this method, it did not give out NO sites for Br. why there is apparent anomalous signal and I cannot identify any Br sites? As Nat pointed out, other atoms should have very weak anomalous signal diffracted at Br absorption peak (3.8e- for Br, versus 0.2e- for the sulfurs). In the difference map, I can clearly see some peaks at high sigma (> 6), but the anomalous difference map(they are all generated by phenix.refine or phenix.maps) is almost featureless, or the peaks has no overlaps. The anomalous difference gives the possible place of Br while the difference map gives the possible place of the whole ligand, and I assume there should be some overlaps between them. Am I right? Charles On Wed, Aug 27, 2014 at 6:28 AM, Gabor Bunkoczi <gb360(a)cam.ac.uk> wrote: > Hi Charles, > > I could be totally misunderstanding what you are trying to achieve, but I > think what you need to do is an MR-SAD calculation. First, solve the > structure with MR (use the macromolecule from the non-Br structure, or use > your current model if you have done refinement on it), and use the > Phaser-EP GUI, and select "SAD starting from MR model". This should > highlight any Br you may have, and gives you a PDB-file with all the peaks > (you can also get a proper anomalous map, but this is only useful for > visualization - the peak search will identify any peaks you may have). > > Let me know if you need more details! > > BW, Gabor > > > On 2014-08-26 14:49, CPMAS Chen wrote: > >> Thanks. Nat. >> >> Since I have some MET and CYT in the protein, could I try to supply >> their sulfur as the initial anomalous scatters? >> >> As for the anomalous isomorphous difference map, would it be useful I >> compare the datasets acquired at 1A wavelength and at the Br >> absorption peak (~0.92A)? >> >> Appreciate your help >> >> Charles >> >> On Mon, Aug 25, 2014 at 5:08 PM, Nathaniel Echols <nechols(a)lbl.gov> >> wrote: >> >> On Sun, Aug 24, 2014 at 6:46 AM, CPMAS Chen <cpmasmit(a)gmail.com> >>> wrote: >>> >>> Here is the point I am not clear. If I am using phenix.refine to >>>> generate LLG map, how do I pick the anomalous group since I have >>>> not placed them in the model yet? >>>> >>> >>> You can't. The LLG map only becomes really useful once you have >>> some anomalous scatterers placed and refined - this is how Phaser >>> substructure completion works. If your molecules have no other >>> significant anomalous scatterers other than the expected Br, the LLG >>> map won't do you much good. >>> >>> By the way, when I choose ion_placement and specify Br, the result >>>> comes with no Br. >>>> >>> >>> Not too surprising, since the code is tuned to look for ions, not >>> part of a covalent molecule, and halides also tend to bond >>> non-specifically and we haven't figured out how to deal with that >>> yet. >>> >>> I want to find whether the Br-containing ligand is seen in my >>>> protein which I have a high resolution structure available. >>>> >>>> I have data collected at Br wavelength, peak or higher position. >>>> Phenix.xtriage reported that the anomalous signal is present to >>>> about 4A. However, both AutoSol or MR-SAD cannot identify the Br >>>> position. Simply say, AutoSol or MR-SAD can not generate any >>>> solution. Well, of course, the simple answer would be that there >>>> is no such ligand cocrystallized. >>>> >>> >>> The simplest explanation is that you just don't have enough >>> anomalous signal to determine the substructure, which can be true >>> even if your ligand is bound. Running experimental phasing to >>> figure this out is unnecessary and time-consuming. >>> >>> Anyway, I am trying to see if the anomalous difference map or >>>> LLG(generated by phenix.maps, this would be the initial one I >>>> assume) can tell me anything more useful. >>>> >>>> So, my question on this topic would be what is a better way you >>>> guys would recommend to identify these Br-ligands? By the way, I >>>> did have the native datasets for the same protein with ligand. >>>> >>> >>> I think in this case I would start with the simple anomalous >>> difference map. If you run phenix.find_peaks_holes (it's in the >>> GUI, of course) and give anomalous data as input, it can pick out >>> the highest peaks in the anomalous map. If the ligand really is >>> bound and the Br site is ordered I would expect this to be >>> detectable. Another alternative is to compute an anomalous >>> isomorphous difference map between a dataset collected at or above >>> (in eV) the Br peak, and a dataset collected below the peak. This >>> will allow you to visualize the wavelength-dependent difference in >>> anomalous scattering, and it's going to be specific for elements >>> with absorption edges within that energy range. But I really don't >>> think this should be necessary to answer your question. >>> >>> -Nat >>> >> >> -- >> >> *************************************************** >> >> Charles Chen >> >> Research Associate >> >> University of Pittsburgh School of Medicine >> >> Department of Anesthesiology >> >> ****************************************************** >> >> >> _______________________________________________ >> phenixbb mailing list >> phenixbb(a)phenix-online.org >> http://phenix-online.org/mailman/listinfo/phenixbb >> > > -- > ################################################## > > Dr Gabor Bunkoczi > > Cambridge Institute for Medical Research > Wellcome Trust/MRC Building > Addenbrooke's Hospital > Hills Road > Cambridge CB2 0XY > ################################################## > -- *************************************************** Charles Chen Research Associate University of Pittsburgh School of Medicine Department of Anesthesiology ******************************************************

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How to tighten ligand geometry in phenix.refine?
by Blankenfeldt, Wulf 29 Aug '14

29 Aug '14

Dear all, I am currently trying to refine a cacodylate ion that partially occupies the phosphate binding site of a PLP cofactor – partially meaning ~90%, in fact I am leaving the PLP out altogether. When I am refining this in phenix. refine, the cacodylate becomes “ugly”: the tetraeder gets slightly squashed and the atoms are flying apart a bit such that they are not automatically connected in Coot any more. I am now wondering if I can tighten the geometry just for the cacodylate to prevent this from happening, either by sending a magical command or by fiddling with the dictionary. Can anyone advise me, please? Regards, Wulf ________________________________ Helmholtz-Zentrum für Infektionsforschung GmbH | Inhoffenstraße 7 | 38124 Braunschweig | www.helmholtz-hzi.de Das HZI ist seit 2007 zertifiziertes Mitglied im "audit berufundfamilie" Vorsitzende des Aufsichtsrates: MinDir’in Bärbel Brumme-Bothe, Bundesministerium für Bildung und Forschung Stellvertreter: MinDirig Rüdiger Eichel, Niedersächsisches Ministerium für Wissenschaft und Kultur Geschäftsführung: Prof. Dr. Dirk Heinz; Franziska Broer Gesellschaft mit beschränkter Haftung (GmbH) Sitz der Gesellschaft: Braunschweig Handelsregister: Amtsgericht Braunschweig, HRB 477

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phenix.refine abort
by sujata halder 28 Aug '14

28 Aug '14

Hi, I am trying to refine a protein with 60 chains (a T=1 virus; 5-3-2 symmetry) and each chain has 520 amino acids. I am using version 1.9 (Release tag: 1692). The job stopped midway and gave the error below followed by "Cannot allocate memory". I have run a similar job (i.e using a similar sized protein) before on an older version (version 1.7) and that had worked. Looking at the error I can't really figure out if the problem is related to installation or a missing module or something different about the code. I can share my files off-list. Here is the error: ====================== XYZ individual (reciprocal space) ====================== R-FACTORS RMSD CLASH RAMA ROTA CBET WEIGHT TARGETS work free delta bonds angl data restr 28.80 29.29 0.49 0.016 1.6 11.9 0.8 7.4 60 none 0.093 160.8996 Traceback (most recent call last): File "/usr/local/phenix-1.9-1692/build/intel-linux-2.6-x86_64/../../phenix/phenix/command_line/refine.py", line 11, in <module> command_line.run(command_name="phenix.refine", args=sys.argv[1:]) File "/usr/local/phenix-1.9-1692/phenix/phenix/refinement/command_line.py", line 163, in run call_back_handler=call_back_handler) File "/usr/local/phenix-1.9-1692/phenix/phenix/refinement/driver.py", line 1577, in run reference_model_manager = self.reference_model_manager).result File "/usr/local/phenix-1.9-1692/phenix/phenix/refinement/strategies.py", line 183, in __init__ ion_placement_manager = ion_placement_manager) File "/usr/local/phenix-1.9-1692/phenix/phenix/refinement/macro_cycle.py", line 114, in __init__ self.call(self.xyzrec, "XYZ individual (reciprocal space)") File "/usr/local/phenix-1.9-1692/phenix/phenix/refinement/macro_cycle.py", line 142, in call func(prefix = prefix) File "/usr/local/phenix-1.9-1692/phenix/phenix/refinement/macro_cycle.py", line 374, in xyzrec prefix = prefix) File "/usr/local/phenix-1.9-1692/phenix/phenix/refinement/xyz_reciprocal_space.py", line 204, in __init__ call_back=(len(trial_weights)==1)) File "/usr/local/phenix-1.9-1692/phenix/phenix/refinement/xyz_reciprocal_space.py", line 314, in try_weight result = self.show(weight=wt, print_stats=print_stats, call_back=call_back) File "/usr/local/phenix-1.9-1692/phenix/phenix/refinement/xyz_reciprocal_space.py", line 365, in show molprobity_scores = self.main.use_molprobity) File "/usr/local/phenix-1.9-1692/cctbx_project/mmtbx/model.py", line 1341, in geometry_statistics molprobity_scores = molprobity_scores) File "/usr/local/phenix-1.9-1692/cctbx_project/mmtbx/model_statistics.py", line 99, in __init__ self.clashscore = clashscore(pdb_hierarchy=pdb_hierarchy).get_clashscore() File "/usr/local/phenix-1.9-1692/cctbx_project/mmtbx/validation/clashscore.py", line 133, in __init__ verbose=verbose) File "/usr/local/phenix-1.9-1692/cctbx_project/mmtbx/validation/clashscore.py", line 257, in __init__ self.run_probe_clashscore(self.h_pdb_string) File "/usr/local/phenix-1.9-1692/cctbx_project/mmtbx/validation/clashscore.py", line 341, in run_probe_clashscore stdin_lines=pdb_string).raise_if_errors().stdout_lines File "/usr/local/phenix-1.9-1692/cctbx_project/libtbx/easy_run.py", line 158, in __init__ close_fds=not subprocess.mswindows) File "/usr/local/phenix-1.9-1692/build/intel-linux-2.6-x86_64/base/lib/python2.7/subprocess.py", line 709, in __init__ errread, errwrite) File "/usr/local/phenix-1.9-1692/build/intel-linux-2.6-x86_64/base/lib/python2.7/subprocess.py", line 1222, in _execute_child self.pid = os.fork() OSError: [Errno 12] Cannot allocate memory ------------------------------------------------------------------------------------------------------------- Thanks, Sujata

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Missing sanity check of duplicate resids within one chain?
by Schubert, Carsten [JRDUS] 28 Aug '14

28 Aug '14

Hi, this is a bit of an esoteric issue I just stumbled over, but I'd like to flag this up anyhow. For some reason (most likely boneheaded error on my side) I wound up with duplicate resids for two ion-atoms: TER HETATM 9325 CL CL S 1 10.578 23.153 35.662 1.00 75.71 Cl1- HETATM 9326 CL CL S 2 -6.546 32.210 31.507 1.00 80.31 Cl1- HETATM 9327 CL CL S 3 21.899 28.037 25.883 1.00 86.22 Cl1- HETATM 9328 K K S 3 7.259 -0.149 19.530 1.00 91.09 K1+ TER Phenix (1.9-1692) seemingly happily accepted the input and proceeded with refinement and validation. After upgrading my coot installation to the latest build the error was flagged. I think this sort of mistake should have at least been flagged in the validation stage or is this out of scope for phenix? Cheers, Carsten

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phenix.maps command line arguments
by Ryan McGreevy 27 Aug '14

27 Aug '14

When using phenix.maps from the command line, passing any arguments for the "map" layer of parameters does not seem to work. For example the command: phenix.maps input.pdb_file_name=input.pdb input.reflection_data.file_name=input.mtz works just fine, but parameters under the "map" section don't seem to have any effect, such as: map.file_name=map.ccp4 map.kicked=True Could I be doing something wrong, or does this not actually work? I know I can set these parameters in a maps.params file, but I would like to be able to pass them on the command line for scripting and automation purposes.

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following on the anomalous map
by CPMAS Chen 27 Aug '14

27 Aug '14

Hi, All Phenix users, I am following this topic. http://www.phenix-online.org/pipermail/phenixbb/2014-April/020622.html. Here is the point I am not clear. If I am using phenix.refine to generate LLG map, how do I pick the anomalous group since I have not placed them in the model yet? By the way, when I choose ion_placement and specify Br, the result comes with no Br. Let me make my situation clear first. I want to find whether the Br-containing ligand is seen in my protein which I have a high resolution structure available. I have data collected at Br wavelength, peak or higher position. Phenix.xtriage reported that the anomalous signal is present to about 4A. However, both AutoSol or MR-SAD cannot identify the Br position. Simply say, AutoSol or MR-SAD can not generate any solution. Well, of course, the simple answer would be that there is no such ligand cocrystallized. Anyway, I am trying to see if the anomalous difference map or LLG(generated by phenix.maps, this would be the initial one I assume) can tell me anything more useful. So, my question on this topic would be what is a better way you guys would recommend to identify these Br-ligands? By the way, I did have the native datasets for the same protein with ligand. Thanks! Charles -- *************************************************** Charles Chen Research Associate University of Pittsburgh School of Medicine Department of Anesthesiology ******************************************************

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Header accuracy after only refining ligands
by Katherine Sippel 26 Aug '14

26 Aug '14

Hi all, I was trying to prep a structure for PDB deposition. All the protein atoms were good, but I needed to correct some ADP and ligand issues. I ran coordinate refinement only on the ligands and subsequent ADP refinement. Everything was good, except the RSMD values output are clearly only for the ligands. Now I am wondering which values in the header I can trust as far as deposition goes. I tried to do a workaround where I ran refine with 0 macrocycles to see if I could get the proper values, but obviously the bulk solvent is different and I get higher R values. I am wondering if I can run validation to get the correct RMSD values or if there are other header values that might have been affected by not refining all the coordinates? Cheers, Katherine -- "Nil illegitimo carborundum"* - *Didactylos

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