May 2016 - Chimera-users - RBVI Mailing Lists

Hidden water molecules
by Michael Sharkey 11 Apr '19

11 Apr '19

Hi I'm trying to visualise water molecules associated with the crystal structure of an enzyme (specifically PDB ID: 1C1D). They're listed when I open the pdb as a text file using WordPad, but I can't for the life of me get them to appear on the screen when I try to visualise the structure in Chimera (v. 1.10.2). What am I missing? Thanks in advance Mike --

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Constrainted fitting
by Christoph Wigge 22 Mar '19

22 Mar '19

Dear all, I would like to fit two protein monomers that form a dimer into an em density map. I know from previous mutagenesis studies that the binding takes place with two tryptophan residues and the counterpart binding pocket. How can I set this interaction as fixed so that chimera fits the rest of the molecule according to the density map without continuously changing this part of the essential protein protein interaction? I would like to fit that interaction manually and then exclude it from the automatic procedure. Thank you very much in advance. Bests Christoph Wigge

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Measuring angles and distances between planes defined by two aromatic rings
by George Tzotzos 26 Sep '16

26 Sep '16

Having generated a 100ns trajectory, I’m interested in measuring the time evolution of the distance between to aromatic ring centroids as well as the angle between the planes of these two rings. The idea is to determine if I’m dealing with pi-pi stacking interactions. I’ve check past correspondence and tried various permutations of commands to no avail. Maybe my best option is to do this for selected snapshots and define for each snapshot two centroids (e.g. c1 and c2) and measure the distance c1 c2. I haven’t managed to find a solution for measuring the angles between the two planes defined by the ring atoms. I’d appreciate any suggestions on possible solutions to the problem described above. I’m attaching a snapshot of measuring distances between two atoms (not really a good solution). Thanks in advance George

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Highlighting the H bonds during simulation
by Natesh Singh 28 Jun '16

28 Jun '16

Dear Sir, How could I highlight the formation and breakdown of Hbonds with the ligand to that of residues during the md simulation. I tried using the script (per-frame commands) chain @ca ~disp solvent hb line 2 color yellow reveal true Using this command, highlights all Hbonds in the system during the simulation, but I would like to see only Hbond interactions with ligand to that of nearby residues. How could I do this? what would be the appropriate per-frame script? Looking forward for the guidance. Best regards, Natesh Uni.Wien

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volume planes tool
by Jeff Triffo 22 Jun '16

22 Jun '16

hi folks, anyone know if the volume plane tool will support arbitrary orientation of the plane any time soon? -Jeff

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Creating maps from models for map/model FSC calculations
by Ardan Patwardhan 03 Jun '16

03 Jun '16

Dear all We are using Chimera to align PDB models to maps, then creating maps from the models using the following command (as an example): molmap #0 5 gridSpacing 1.3 This should create a map with the voxel spacing of 1.3A and a gaussian atom spread function with the width related to 5A resolution (https://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/molmap.html). Our problem is a) the map that is created can have an arbitrary size - we need it to be cubic and have the same (known) dimensions as the second map against which it will be compared b) we have tried padding it in other programs like bsoft but then we sometimes run into problems of centring the model. I was wondering if there was a way to get a centred map of a certain size from a model directly from Chimera? Perhaps there are certain parameters that can be used in molmap? You thoughts and advice on this issue are much appreciated! Many thanks and best wishes Ardan Patwardhan Coordinator - cellular structure & PDBe production Protein Data Bank in Europe (PDBe) European Bioinformatics Institute (EMBL-EBI) European Molecular Biology Laboratory Wellcome Trust Genome Campus Hinxton, Cambridge CB10 1SD Tel: +44 1223 492649

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Re: [Chimera-users] Analysis of the contact maps from the MARTINI MD trajectory
by James Starlight 01 Jun '16

01 Jun '16

Yep thanks so much Eric! In my case the contacts have been started to be recognized both from only after choosing the vdw cutoff > -4.0 A and decreasing statistical (weight discard edge threshold) factor to 0.3 (here I am analyzing big trajectory consisted of 7 independent MD trajectories for the same system merged together where both proteins are present both in bound and unbound states during the progression of simulation). Eventually I obtained LYS 25.A vdw SER 712.C 0.39322 CYS 14.A vdw TRP 1586.I 0.427119 HIS 33.A vdw ions 0.335593 HIS 33.A vdw LYS 1577.I 0.444068 LYS 27.A vdw TRP 1586.I 0.369492 GLU 838.C vdw PHE 46.A 0.444068 GLN 12.A vdw TRP 1586.I 0.501695 ASP 1580.I vdw LYS 7.A 0.318644 PHE 46.A vdw TRP 1586.I 0.491525 GLU 732.C vdw LYS 79.A 0.372881 PHE 46.A vdw solvent 0.501695 CYS 1584.I vdw HIS 26.A 0.616949 HIS 26.A vdw SER 712.C 0.423729 ASP 1580.I vdw LYS 8.A 0.305085 TYR 1542.I vdw VAL 11.A 0.311864 LYS 27.A vdw solvent 0.40678 THR 28.A vdw TYR 731.C 0.379661 PHE 46.A vdw TYR 1587.I 0.484746 Also may I ask within this output the first column should correspond to first selection, right? here the contacts was defined as between atoms from chain A which is the smaller protein and the rest of the system consisted of atoms of receptor. Thanks again! Gleb 2016-05-17 22:37 GMT+02:00 Eric Pettersen <pett(a)cgl.ucsf.edu>: > Well, if I were you I would go to a trajectory frame that I think should have contacts, and then bring up the Find Clashes/Contacts tool (in the Structure Analysis category of Tools) and play around with the criteria to see what yields contacts. You might also change the atoms to sphere mode (Actions->Atoms/Bonds->sphere) to see if they have any VDW overlap or are close. You might also measure some distances (control-click an atom, then control-shift-double-click a second atom and then pick “Show Distance” from the popup menu). Without actual access to your data, I can’t offer any more specific suggestions. > > —Eric > >> On May 17, 2016, at 2:08 AM, James Starlight <jmsstarlight(a)gmail.com> wrote: >> >> Thanks Eric! >> >> it quite strange that no interactions are found- because in my >> trajectory the complex between both proteins are emerged very soon >> after beginning of the simulation and is quite stable until ed of it. >> Seems like the Chimera does not recognize martini's CG atoms properly. >> Are there any suggestions to fix it e.g by the variations using any of >> options - e.g vdw settings etc? >> >> Gleb >> >> 2016-05-17 1:32 GMT+02:00 Eric Pettersen <pett(a)cgl.ucsf.edu>: >>> The clustering is based on least-squares-fit RMSDs between corresponding atoms, and therefore global translations and rotations are irrelevant. >>> >>> —Eric >>> >>>> On May 16, 2016, at 9:08 AM, James Starlight <jmsstarlight(a)gmail.com> wrote: >>>> >>>> update :-) >>>> >>>> in addition to the previous question which is still actual I am >>>> interesting in the clusterization of binding interfaces established >>>> during MD e.g based on the position of one protein regarding another. >>>> >>>> For my case I have performed such clusterization from MD movie plugin >>>> (which was based on current selection which was the atoms of smaller >>>> protein) obtaining alot of overlapped clusters in case of smallest >>>> step size and afew clusters increasing step size twisly. Is it >>>> possible here to increase accuracy of the clusterization and to remove >>>> some degrees of freedom which are not important for my case ? E.g to >>>> pre-process trajectory using PCA before clusterization to discard >>>> rotation translation of the system will be good option? >>>> >>>> >>>> >>>> James >>>> >>>> 2016-05-16 15:20 GMT+02:00 James Starlight <jmsstarlight(a)gmail.com>: >>>>> update : >>>>> >>>>> already playing with the plugin MD movie and "residue iteration >>>>> network within the trajectory" tool >>>>> just selecting atoms from the chain A as 1st selection >>>>> and other atoms from other chains as 2nd selection >>>>> >>>>> running calculation (trying to varry cut-off corresponded to vdw overlap radii) >>>>> >>>>> obtained error >>>>> AttributeError: 'ResInteractionDialog' object has no attribute 'markers' >>>>> >>>>> File "/opt/UCSF/Chimera64-1.10.2/share/Movie/ResInteraction.py", >>>>> line 535, in Apply >>>>> markerSettings = [(m['xy'], m['rgba']) for m in self.markers] >>>>> >>>>> See reply log for Python traceback. >>>>> >>>>> Does it means that somethig special should be specified for the >>>>> MARTINI CG atoms? >>>>> >>>>> Thanks ! >>>>> >>>>> Gleb >>>>> >>>>> 2016-05-16 12:13 GMT+02:00 James Starlight <jmsstarlight(a)gmail.com>: >>>>>> something relevant in my model: >>>>>> >>>>>> this is martini CG model consisted of big membrane protein and small >>>>>> water soluble protein. In my particular trajectory I have only atoms >>>>>> of both proteins recognized by chimera as individual chains (e.g small >>>>>> protein is chain A and the biggest is consisted of chains B-N). >>>>>> >>>>>> Gleb >>>>>> >>>>>> 2016-05-16 11:58 GMT+02:00 James Starlight <jmsstarlight(a)gmail.com>: >>>>>>> update: >>>>>>> >>>>>>> with the up-to-date chimera Trajectory is loaded fine >>>>>>> now the question is related to the analysis of the binding interface. >>>>>>> is it possible to make contact maps plots based on the 2 selections >>>>>>> from the input trajectory assuming that I am using martini CG model? >>>>>>> >>>>>>> Gleb >>>>>>> >>>>>>> 2016-05-16 10:39 GMT+02:00 James Starlight <jmsstarlight(a)gmail.com>: >>>>>>>> OK will try to update Chimera today ! >>>>>>>> >>>>>>>> What chimera's tools could be useful for the contact map based >>>>>>>> analysis of md trajectories related to my case ? E.g to determine >>>>>>>> binding interface between 2 proteins from long md simulation. >>>>>>>> >>>>>>>> Gleb >>>>>>>> >>>>>>>> 2016-05-13 19:52 GMT+02:00 Eric Pettersen <pett(a)cgl.ucsf.edu>: >>>>>>>>> Hi Gleb, >>>>>>>>> If you are using Gromacs 5 trajectories, you have to be using at least >>>>>>>>> version 1.10.2 of Chimera. If you are using that version (or later), please >>>>>>>>> use “Report a Bug” in Chimera’s Help menu to file a bug report and attach >>>>>>>>> your topology file to the bug report. Thanks! >>>>>>>>> >>>>>>>>> —Eric >>>>>>>>> >>>>>>>>> Eric Pettersen >>>>>>>>> UCSF Computer Graphics Lab >>>>>>>>> >>>>>>>>> >>>>>>>>> On May 13, 2016, at 1:46 AM, James Starlight <jmsstarlight(a)gmail.com> wrote: >>>>>>>>> >>>>>>>>> Dear Chimera users! >>>>>>>>> >>>>>>>>> >>>>>>>>> I am in charge with the analysis of protein-protein association during >>>>>>>>> long molecular dynamic simulation where my system was parametrized >>>>>>>>> using MARTINI CG force field. In particularly I am interesting to >>>>>>>>> find residues on one of the protein which are crustal for the binding >>>>>>>>> interface established during this MD. >>>>>>>>> For that purpose I am trying to use Chimera to load trajectory and >>>>>>>>> corresponded tpr file using MD movie plugin and than to >>>>>>>>> map contact maps produced by Gromacs onto the 3D structure using Chimera. >>>>>>>>> The problem that Chimera does not recognize properly the trajectory >>>>>>>>> and topology. Briefly I have removed all solvent from both files >>>>>>>>> before loading them to the Chimera using editconf and gmx convert-tpr >>>>>>>>> obtaining eventually trajectory and topology with the same number of >>>>>>>>> atoms. >>>>>>>>> >>>>>>>>> >>>>>>>>> Than when I load it to Chimera that is the error which MD movie sent me: >>>>>>>>> >>>>>>>>> VERSION 5.0.2 >>>>>>>>> using floats >>>>>>>>> version 100, generation 26 >>>>>>>>> 8 atoms >>>>>>>>> Traceback (most recent call last): >>>>>>>>> File "CHIMERA/lib/python2.5/site-packages/Pmw/Pmw_1_3/lib/PmwBase.py", >>>>>>>>> line 1747, in __call__ >>>>>>>>> File "CHIMERA/share/chimera/baseDialog.py", line 328, in command >>>>>>>>> File "CHIMERA/share/chimera/baseDialog.py", line 543, in OK >>>>>>>>> File "CHIMERA/share/Trajectory/EnsembleLoader.py", line 92, in Apply >>>>>>>>> File "CHIMERA/share/Trajectory/formats/Gromacs/__init__.py", line >>>>>>>>> 56, in loadEnsemble >>>>>>>>> File "CHIMERA/share/Trajectory/formats/Gromacs/__init__.py", line >>>>>>>>> 67, in loadEnsemble >>>>>>>>> File "CHIMERA/share/Trajectory/formats/Gromacs/Gromacs.py", line 25, >>>>>>>>> in __init__ >>>>>>>>> File "CHIMERA/share/Trajectory/formats/Gromacs/Gromacs.py", line 86, >>>>>>>>> in __init__ >>>>>>>>> File "CHIMERA/share/Trajectory/formats/Gromacs/Gromacs.py", line >>>>>>>>> 345, in _readTopology >>>>>>>>> File "CHIMERA/share/Trajectory/formats/Gromacs/Gromacs.py", line >>>>>>>>> 338, in _readString >>>>>>>>> File "CHIMERA/lib/python2.5/xdrlib.py", line 197, in unpack_fstring >>>>>>>>> raise EOFError >>>>>>>>> EOFError >>>>>>>>> EOFError >>>>>>>>> >>>>>>>>> File "CHIMERA/lib/python2.5/xdrlib.py", line 197, in unpack_fstring >>>>>>>>> raise EOFError >>>>>>>>> >>>>>>>>> See reply log for Python traceback. >>>>>>>>> >>>>>>>>> Will be thankful for any suggestions! >>>>>>>>> >>>>>>>>> Gleb >>>>>>>>> _______________________________________________ >>>>>>>>> Chimera-users mailing list: Chimera-users(a)cgl.ucsf.edu >>>>>>>>> Manage subscription: >>>>>>>>> http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users >>>>>>>>> >>>>>>>>> >>>> >>>> _______________________________________________ >>>> Chimera-users mailing list: Chimera-users(a)cgl.ucsf.edu >>>> Manage subscription: http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users >>>> >>> >> >

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Rotamers in Chimera
by Lew Jacobson 01 Jun '16

01 Jun '16

I am using Chmiera 1.10 build 40304 on a Mac. (I am a leftover Midas user!) So far as I can tell, this version is still using the Dunbrack 2002 rotamer library. Is any subsequent version using the improved 2011 Dunbrack library? If not, can you instruct me how to incorporate that newer library into Chimera? thanks, Lew Jacobson -- Dr. Lewis Jacobson Professor of Biological Sciences Univ. of Pittsburgh Pittsburgh PA 15260 412-624-4647 Fax 412-624-4759 LJAC(a)pitt.edu

2 1

Can I use wait command over Rest service?
by Mungo Carstairs (Staff) 31 May '16

31 May '16

Hi, I am trying to devise a way to highlight locations on a structure in Chimera while mousing over the sequence in Jalview. My latest attempt tries to 'flash' the side-chain display at the residue position i.e. - hide then show atoms (if currently displayed e.g. display is in atom mode) - or show then hide atoms (if currently not displayed e.g. display is in ribbon mode) I'm sending a command like display #0:30.A;wait 20;~display #0:30.A to the Rest service. However while this seems to do what I want when used at the Chimera command line, via the Rest service it ignores the wait command, with the result that the action is too quick to see. Any suggestions please for how to get this to work, or a better alternative? Thanks, Mungo Mungo Carstairs Jalview Computational Scientist The Barton Group Division of Computational Biology School of Life Sciences University of Dundee, Dundee, Scotland, UK. www.jalview.org<http://www.jalview.org/> www.compbio.dundee.ac.uk<http://www.compbio.dundee.ac.uk/> The University of Dundee is a registered Scottish Charity, No: SC015096

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broken lines
by shazia sabir 29 May '16

29 May '16

Hi dear All, Why chimera is showing broken lines (region encircled in red at one area). What can we predict from structure. I attached sequence of structure that shows amino acid is there(gey region in sequence). Regards, shazia.

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Chimera-users May 2016