- Chimera-users - RBVI Mailing Lists

Access to "Match Align" programmatically
by Miguel Ortiz Lombardía 26 Oct '15

26 Oct '15

Hi, Is it possible to call "Match Align" from a script or a 'com' file without using the GUI? I would use that possibility, if it does exist, to check pair-wise rmsd's of previously superimposed structures. I guess people may have asked this question before, but I couldn't find an answer in the usual places... Cheers, Miguel

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Query on Cryo-EM map
by Aditya Padhi 25 Oct '15

25 Oct '15

Dear Chimera Users, I have a cryo-em map file and I would like to convert it into a PDB file. How can I do that? I tried saving the .pdb file but it throws an error saying “No model chosen to save”. Another question, If I open a .map file of a protein complex in Chimera, how can I select a subregion (a particular chain) and colour the surface of that part differently? I am not able to select the chain when I upload the .map file. Thank you, Aditya

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How to make a microtubule model
by Tom Goddard 22 Oct '15

22 Oct '15

The following page shows a “bent microtubule” model made with a Chimera Python script https://www.cgl.ucsf.edu/chimera/data/microtubule_aug2013/bent_mt.html <https://www.cgl.ucsf.edu/chimera/data/microtubule_aug2013/bent_mt.html> The bend makes it more complicated than a straight microtubule. Here is an explanation of how the Chimera “sym” command can make a straight microtubule model. These commands in Chimera (menu Favorites / Command-line to enter commands) make a straight microtubule from a PDB model as shown in the attached image. open 1jff sym #0 group h,9.8,27.7,13*shift,8,80.0 surf true axis x center 0,115,0 res 5 The sym command took the tubulin dimer (shown in red and blue in the image) and made copies in a helical pattern to look like a microtuble. The trick is to find the right helical parameters. I just did a few minutes trial and error to find the above. The “group” option says make a helix where each subunit is shifted 9.8 Angstroms from the previous one and by 27.7 degrees around the axis from the previous one, and make 13 copies (for a 13 protofilament microtubule). This makes a single turn of the microtubule. A microtubule does not have helical symmetry, the one turn achieves a shift of 1.5 subunits creating a seam where alpha and beta tubulin are touching in two adjacent protofilaments. So I just make one turn. Then the above command says shift that one turn by 80 Angstroms along the axis for each of 8 copies. The “surf true” option says show the copies as surfaces. Without that it will copy the atomic model and use a ton of memory. The helix axis is x (just judged by eye after opening tubulin dimer 1jff. The 1jff dimer seems to be centered not far from 0,0,0 so I shifted the helix axis 115 Angstroms along y to make the diameter about 23 nm. Here are the docs for the sym command: http://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/midas/sym.html <http://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/midas/sym.html> Here’s a web page where I did something more sensible to get better symmetry parameters — I fit the tubulin dimer to an EM map of a microtubule. http://www.cgl.ucsf.edu/chimera/data/cellcomplexity06/tcell-demo.html <http://www.cgl.ucsf.edu/chimera/data/cellcomplexity06/tcell-demo.html> Tom

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center of mass
by erik.laurini＠di3.units.it 21 Oct '15

21 Oct '15

Dear Chimera users, I would to plot the distance between the centers of mass of a ligand and a specific portion of its biologic target during the corresponding MD trajectory. I tried with the "MD plot" but it seems that it works only with atom selection. Do you have any advice? Thanks in advance! -erik- Dr. Erik Laurini Department of Engineering and Architecture University of Trieste, Via Valerio 10, 34127, Trieste (Italy) Tel. + 39 0405583440

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Calculating the total areaSAS from a series of PDB files
by ros 21 Oct '15

21 Oct '15

Hello! I would like to measure the SAS from a series of PDB files to see how the surface value changes over time (the PDB files are from an MD simulation). I know that If I open a PDB file and calculate the surface, I get the areaSAS value, but I do not want to do this 5000 times. I am making progress on a python script to automate the process, which is: -------------------------------------------- import os from chimera import runCommand as rc from chimera import replyobj os.chdir("/home/tmp/pdb") file_names = [fn for fn in os.listdir(".") if fn.endswith(".pdb")] for fn in file_names: replyobj.status("Processing " + fn) rc("open " + fn) rc("surf") rc("sel :1-6") from chimera.selection import currentResidues residues = currentResidues() outf = open("/home/tmp/sas.dat", "w") for r in residues: print>>outf, r, r.areaSAS rc("stop now") -------------------------------------------- The PDB's consist of only 6 residues (DNA residues). With this script, I get the output: #1 DA 1 320.8377808 #2 DC 3 277.614161432 #2 DG 4 323.883637217 #1 DC 3 284.934065707 #2 DT 6 221.04715555 #0 DA 1 321.883850728 #1 DC 5 345.231659889 #0 DC 2 179.379177183 #2 DC 5 350.455405176 #0 DC 3 285.785918236 #1 DT 6 245.048330456 #0 DG 4 303.501165912 #1 DG 4 314.409510799 #0 DC 5 352.639633257 #1 DC 2 193.509086639 #0 DT 6 214.883334659 #2 DC 2 183.766654447 #2 DA 1 344.369126737 using 3 test pdb's. Is there a way to get the total value of areaSAS of each model and not for each residue? I am interested in having a file just like (using for example 3 pdb's): Model # total areaSAS value #0 123123.123122 #1 123123.12312 #3 123123.12312 ... etc. I have tried deleting the residues loop, but I do not know how the total areaSAS attribute is stored or how to assign it to a variable. Thank you for your help! Rodrigo. PS. The main goal is to be able to do this without the PDB files and just reading an AMBER topology/trajectory...

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Change chain id of blank chain
by Tom Goddard 20 Oct '15

20 Oct '15

Hi Joshua, Eric looked at the code and said the changechains command can’t change the blank chain id because it won’t accept a quoted space character as the chain letter. It could be done with Python code, or as you mention you can do it with the change chain ids gui. Tom > On Oct 20, 2015, at 2:07 PM, Broyde, Joshua E. <wrote: > > Dear Tom, > Hope you are well. I am having an issue with redefining the chains in a pdb open in Chimera. If a model has two chains (A and B) then it is easy to reassign the chain ids using: > changechains A,B B,A > > However, if one of the chains does not have a chain id already, (what Chimera calls, the "principle chain"), how do I assign a chain id? This is easy to do in the GUI, but I cannot find a command for doing so. > > Sincerely, > Joshua Broyde

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Color blobs automatically
by Petr.Brazda＠seznam.cz 19 Oct '15

19 Oct '15

Hello, I have both periodically distributed blobs and blobs, which are randomly distributed in my volume data. I know the translational vectors of the periodic net of blobs and I would like to automatically color them to distinguish them from the rest of the blobs. Is there a way to tell Chimera to color the blobs, which contain voxel with particular x, y, z coordinates? Or is there some other way to do this job? Best regards, Petr

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mouse selection not working
by Joel Meyerson 19 Oct '15

19 Oct '15

Hi, I'm unable to click-and-drag to select objects in the latest version of Chimera. Specifically, when I hold 'ctrl' and drag over an object, no selection is made. This is something that worked just fine in previous versions of the program. Any suggestions on how to fix the issue? I'm using Chimera production version 1.10.2 (build 40686) and running Mac OS X 10.10.4. Thanks, Joel

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on movie command
by Smith Liu 18 Oct '15

18 Oct '15

Dear All, Suppose there is a 100-residue protein opened in chimera, and it was scaled to a windows which can hold 10 residues, for example residue 10-20. Is any good way we first center on residue 15, then smoothly center on residue 16 (window hold residue 11-21), then smoothly center on residue 17 (window hold residue 12-22), then smoothly center on residue 18 (window hold residue 13-23), ......., until we center on residue 100? Here I emphasize "smoothly" so that the residue "move" was not too sudden to the eye. Best regards. Smith

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label residues
by Albert 17 Oct '15

17 Oct '15

Hello: I got a question on label residues in Chimera. Is it possible to use a simple command line to label all protein residue name and number displayed in the workspace? Thanks you very much Albert

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can you provide more opition for webGL?
by Albert 16 Oct '15

16 Oct '15

Hello everybody: I am just fascinated by the webGL function in Chimera and I am googling it today. Here I found something is even more interesting: http://istar.cse.cuhk.edu.hk/iview/ As far as we can see, it provide much more options in the above link. I am just wondering, could the Chimera developer also consider provide more options for the exported webGL file? That's definitely would be very attractive for the users. Thanks a lot Albert

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uneditable format
by Oliver Clarke 16 Oct '15

16 Oct '15

Hi Eric, I had no idea you could do this, it works great and could be very handy!! The colors and lighting (and positions) don’t seem to be preserved though and differ between firefox and safari - see the attached screenshots and test webgl of 1BL* with EDS maps (WebGL link: https://www.dropbox.com/s/jlwt8ynrz59w5qx/test_webgl.html?dl=0 <https://www.dropbox.com/s/jlwt8ynrz59w5qx/test_webgl.html?dl=0>). Oli. > Hi Albert, > Look at the File->Export Scene menu. That allows you to export to various file formats that your recipient may be able to view without any easy ability to save the result as a PDB file. In particular the “WebGL” export can be viewed as a web page in most modern browsers, with the ability to manipulate the structure interactively. > > —Eric > > Eric Pettersen > UCSF Computer Graphics Lab > > > > On Oct 16, 2015, at 6:41 AM, Albert <mailmd2011 at gmail.com <http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users>> wrote: > > > > Hello: > > > > I've made a Chimera section which I would like to share with somebody else. However, I don't want the PDB within Chimera section to be exported by others. Is it possible for us to export some special file format so that other users can only visualize my file, but they cannot edit or export file into PDB coordinate? > > > > Thanks a lot > > > > Albert > > _______________________________________________ > > Chimera-users mailing list > > Chimera-users at cgl.ucsf.edu <http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users> > > http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users <http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users>

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uneditable format
by Albert 16 Oct '15

16 Oct '15

Hello: I've made a Chimera section which I would like to share with somebody else. However, I don't want the PDB within Chimera section to be exported by others. Is it possible for us to export some special file format so that other users can only visualize my file, but they cannot edit or export file into PDB coordinate? Thanks a lot Albert

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Failure to reproduce complete Consurf output
by George Tzotzos 16 Oct '15

16 Oct '15

Hi everybody, I’m attaching a snapshot of the output of a Consurf job (snapshot1). Trying to save the file in EPS format produces only A PART of the right-hand-side pane of the output. No histogram is produced (see output.eps). I’d appreciate any suggestions as to how to produce a complete output. Thank you in advance George

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Re: [Chimera-users] uneditable format
by Oliver Clarke 16 Oct '15

16 Oct '15

Hi Albert, I'm pretty sure this doesn't exist at present, and I guess it would require substantial changes to make it work - You'd need to make sure that chimera couldn't write out anything after reading that session, and given that Chimera is open source and has many different ways of writing data out that might be tricky. However, that said, I think having a read-only packaged session format would be a very valuable addition (particularly if it incorporated support for maps), because it would solve a long standing issue in peer review of structural biology results - how to provide raw data for inspection to reviewers without providing maps and models with no strings attached, which many PIs are disinclined to do. Cheers, Oliver. >Hello: > >I've made a Chimera section which I would like to share with somebody >else. However, I don't want the PDB within Chimera section to be >exported by others. Is it possible for us to export some special file >format so that other users can only visualize my file, but they cannot >edit or export file into PDB coordinate? > >Thanks a lot > >Albert

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on mrz file
by Smith Liu 16 Oct '15

16 Oct '15

Dear All, Suppose I have 2 mrc files which are similar on the same protein, we call one map A one map B, and suppose onece we open them by chimera, A was in the centre of the window and B was not. By mouse dragging we moved map B almost overlap with chain B, then we fit map B to map A by the chimera "Fit in map" function. Is any way we can save map B, so that when we open map A and the saved map B by chimera, both A and B were in the centre of the Windows and A and B fitted as just before we saved map B? Best regards. Smith

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on scale command
by Smith Liu 15 Oct '15

15 Oct '15

Dear All, If I have used "scale 1.04" to scale up, will you please tell me the factor x in "scale x" by which I can return to the original size before I used "scale 1.04" ? Best regards. Smith

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Suggestion - autofilter history by typed substring?
by Oliver Clarke 14 Oct '15

14 Oct '15

Hi all, Just a suggestion (I guess for chimera 2) - would it be possible to autofilter the command history based on the typed substring? That is if I have typed “sel” and hit the up arrow, to only cycle through those commands in the history that start with “sel”. This would be particularly handy for scrolling quickly through recent “sel” and “color” commands - a similar mechanism is implemented in several shells and it works well. Cheers, Oliver.

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Re: [Chimera-users] Interactive Protein Structure and Sequence Alignment?
by Elaine Meng 14 Oct '15

14 Oct '15

On Oct 13, 2015, at 6:44 PM, Abba Leffler <aleffler(a)alumni.princeton.edu> wrote: > Dear Professor Meng, > I'm a frequent user of Chimera, mostly for visualization of homology models of large complexes. There's one feature I've search for in Chimera and not found. I wonder if you can help me. > > I would like to do two things, which are related. > > First, I would like to be able to visualize where inserts, deletions, and mutations are on the template structure relative to the target sequence. Is there any way to do that? I haven't found one. > > In a related question, I'd like to be able to interactively edit the sequence alignment (i.e. move indels that are in secondary structure elements) and then recompute the homology model to see if the DOPE score gets better or worse. Is that a possibility? > > I've found that many people have told me that alignments have to be "manually corrected", but there don't seem to be many tools out there for doing that in a sane way. If there are any you could recommend, I would sincerely appreciate it. > > All best, > -Abba Dear Abba, (1) Any time you have a structure open in Chimera and associated with some sequence in MultAlign Viewer (Chimera’s sequence viewer), you can easily map between the sequence and structure. It can be an individual sequence or one within a multiple sequence alignment. You can just highlight an area of interest on the sequence with the mouse and it will be highlighted on the structure. See the Sequences and Structures tutorial: <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/tutorials/super.html> … and/or the Multalign Viewer documentation, especially the part about sequence-structure association: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/f…> <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/m…> If you used the Modeller interface in Chimera, you already have the target-template sequence alignment open in Chimera. Then you could just use the mouse to highlight where in the sequence there is a mutation or insertion to have it highlighted on the structure(s). Actually this does selection. Then you can use the Actions menu to do something (e.g. coloring) to the current structure selection. While you can’t highlight something in the sequence that isn’t there (a deletion), you could certainly highlight the positions around it. (2) Multalign Viewer does allow for some small amount of manual editing, but it is not optimized for this purpose and other programs should be more suitable for any serious amount of editing. However, I don’t do this myself so I cannot advise... maybe JalView? Here are the instructions for manual editing in Multalign Viewer: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/m…> I hope this helps. I’ve CC’d this reply to chimera-users, which is the address we recommend for asking Chimera questions. Best, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco

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Announcing the 2015/2016 EMDataBank Model Challenge
by Cathy Lawson 14 Oct '15

14 Oct '15

Dear Chimera User List Members, EMDataBank is pleased to announce the 2015/2016 Model Challenge. All members of the Scientific Community--at all levels of experience--are invited to participate as Challengers, and/or as Assessors. Benchmark targets of varying size and complexity have been selected from recently deposited 3DEM structures based on current state-of-the-art detectors and processing methods, in the resolution range 2.2-4.5 Å. Challengers are sought to create and validate models from challenge target maps in four different categories (1. optimize current cryoEM model, 2. fit known related cryoEM, crystallographic, or comparative models, 3. ab initio model building, 4. any other method of map interpretation), and upload their results with associated details. Assessors are sought to participate in evaluating submitted models. Registration is now open for all interested participants. Challengers may submit their models between November and April. Before submissions open, all are encouraged to provide feedback on submission requirements. An open assessment period will commence in late 2016. To learn more about this challenge and to register, please visit http://challenges.emdatabank.org and click on "MODEL CHALLENGE" in the menu bar. This is the second of two community-wide challenges being sponsored by EMDataBank this year to critically evaluate 3DEM methods that are coming into use, with the ultimate goal of developing validation criteria associated with every 3DEM map and map-derived model. The first challenge is focused on creating reconstructions from raw 2D image data and is currently in progress (click on "MAP CHALLENGE" in the menu bar). Sincerely, Cathy Lawson on behalf of the EMDataBank Team and the Model Challenge Committee emdatabank.org www.facebook.com/emdatabank3dem

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Show symmetry axis?
by Oliver Clarke 14 Oct '15

14 Oct '15

Hi all, Is there any way to easily generate an axis (of the type created by define axis, not a BILD file) corresponding to the z-axis of a map? Or of the symmetry axis of a map as identified by measure symmetry (which should be the same thing I guess)? I would like to be able to align Cn symmetric maps, which in general have the Cn symmetry axis coincident with z, while strictly obeying the Cn symmetry of the map. There is no built-in way to do this in chimera that I know of, but if I could create an axis corresponding to z for both maps, I could measure correlation between the two maps about that axis, after first aligning the symmetry axes of the two maps and approximately matching their translations along that axis (incidentally, for the same purpose it would be handy to have an additional option for "measure correlation rotationaxis", to measure correlation in a distance range corresponding to +/- x Å from the current position along the specified axis - angleRange is currently present, “distanceRange” seems like it could be a useful extension). The closest I have come so far is the following alias: alias ^screen_axis cofr view; savepos tmp; ac mc; namesel z1; clip hither -50;clip yon -50;cofr view; ac mc; namesel z2; sel z1 | z2; define axis sel; ~disp sel; reset tmp This will generate an axis perpendicular to and in the center of the screen, but this seems like a bit of a hack… also when I use measure correlation with this axis ("measure correlation #2 #0 rotationAxis a1”, where #2 and #0 are the two maps and the axis is a1), I get the attached error - is this a bug or did I make a stupid mistake somewhere? Cheers, Oliver.

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Show symmetry axis?
by Oliver Clarke 14 Oct '15

14 Oct '15

Actually never mind… just realized I have requested similar previously and there is already a ticket open (http://plato.cgl.ucsf.edu/trac/chimera/ticket/13829 <http://plato.cgl.ucsf.edu/trac/chimera/ticket/13829>). Nevertheless, consider this another vote for constraining fitmap to the symmetry of the input maps (or models) - would be very very helpful when dealing with ion channels. Cheers, Oliver. > > Message: 1 > Date: Tue, 13 Oct 2015 20:13:37 -0400 > From: Oliver Clarke <olibclarke(a)gmail.com> > To: "chimera-users(a)cgl.ucsf.edu BB" <chimera-users(a)cgl.ucsf.edu> > Subject: [Chimera-users] Show symmetry axis? > Message-ID: <5DBFD175-0F48-4731-9E7E-C3F635BC571D(a)gmail.com> > Content-Type: text/plain; charset="utf-8" > > Hi all, > > Is there any way to easily generate an axis (of the type created by define axis, not a BILD file) corresponding to the z-axis of a map? Or of the symmetry axis of a map as identified by measure symmetry (which should be the same thing I guess)? > > I would like to be able to align Cn symmetric maps, which in general have the Cn symmetry axis coincident with z, while strictly obeying the Cn symmetry of the map. > > There is no built-in way to do this in chimera that I know of, but if I could create an axis corresponding to z for both maps, I could measure correlation between the two maps about that axis, after first aligning the symmetry axes of the two maps and approximately matching their translations along that axis (incidentally, for the same purpose it would be handy to have an additional option for "measure correlation rotationaxis", to measure correlation in a distance range corresponding to +/- x ? from the current position along the specified axis - angleRange is currently present, ?distanceRange? seems like it could be a useful extension). > > The closest I have come so far is the following alias: > > alias ^screen_axis cofr view; savepos tmp; ac mc; namesel z1; clip hither -50;clip yon -50;cofr view; ac mc; namesel z2; sel z1 | z2; define axis sel; ~disp sel; reset tmp > > This will generate an axis perpendicular to and in the center of the screen, but this seems like a bit of a hack? also when I use measure correlation with this axis ("measure correlation #2 #0 rotationAxis a1?, where #2 and #0 are the two maps and the axis is a1), I get the attached error - is this a bug or did I make a stupid mistake somewhere? > > Cheers, > Oliver. > > > > >

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drawing single stranded dna
by Sanders, Melanie - ARS 13 Oct '15

13 Oct '15

Dear, Is it possible to draw a single stranded dna. I always get a double stranded one if I enter the nucleic acids. Best regards, Melanie Sanders, PhD. Mycotoxin Prevention and Applied Microbiology USDA-ARS 1815 North University Street Peoria, Illinois 61604-3999 Phone: 309-681-6208 e-mail: melanie.sanders(a)ars.usda.gov<mailto:melanie.sanders@ars.usda.gov>

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output hdf5
by gijs 13 Oct '15

13 Oct '15

Dear Sir/Madam. First of all I want to complement the chimera team for writing a fantastic package for view macromolecular complexes. I am a researcher from the coherent X-ray diffraction community and we are also producing 3D models using our software [1]. However, we write data in a hdf5 format. Would you be interested to incorporate our file system into your package, or, and I think this is for now the better solution, could you provide a way I can write my hdf5 file to a chimera readable format and visa versa? For instance, I am trying to open a .map file from the EM databank, but do not know to exactly how to convert it. Are there tools? What file tree in hdf5 do I need? With kind regards, Gijs van der Schot [1] http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.114.098102

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on 2d label related movie command
by Smith Liu 13 Oct '15

13 Oct '15

Dear All, By chimera is any method we label a residue in a protein after scaling-up around that residue in a movie? Best regards. Smith

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