- Chimera-users - RBVI Mailing Lists

mask using volume contour surface
by gongpu zhao 13 May '13

13 May '13

Hi All, I have a question about volume contour surface in chimera. I have a density volume of a shell shape. I plan to use the outer contour surface of the volume to mask out all density encased by the outer surface in a tomogram. But instead, I could only mask out the density within the shell. I am wondering if I can make a surface model only using the outer surface. Thanks a lot. Gongpu

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About Morph Conformations
by 吕柯 13 May '13

13 May '13

Dear Sir./Madam, I am a graduate student in Chinese Academy of Sciences. I have two PDB files: one for virus(4 chains, PDB:3VBS), the other for empty particle(3 chains, PDB:3VBU). I would like to use Morph Conformations to make movie for that. However, it turns out "Can not interpolate models: models have different number of chains". Could you please show me what should I do next? Thanks a lot. Yours, Lyu Ke -- Lyu Ke, Ph.D. student Structural Virology Unit Institut Pasteur of Shanghai Chinese Academy of Sciences No.411 Hefei Road Shanghai, 200025, P.R. China Tel: +86-21-54920652

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Re: [Chimera-users] saving sessions
by Tom Goddard 08 May '13

08 May '13

Hi Thomas, There is no session saving option that copies density map files to the same directory as the session file. All other Chimera models including PDB files are included (not linkied) in the session file. The reason maps are not put into the session file is because they are sometimes very large, Gbytes in size. Some day I intend to add an option to include the maps in the session file so you can have a self-contained session if you want. Copying the files could be another approach but it has problems. What if there is already a map with the same file name in the current directory? Could modify the copied file name I guess. Maybe better put all the map files in a new subdirectory. But are you really going to make copies of all the map files on every session save? If you only do it sometimes it doesn't solve the problem of moving data to a new computer. It will be slow to copy the files and it makes many redundant copies which then can become confusing as to whether two files with the same name really are identical. Hard links could be used to avoid copying the file, but that won't work when a session is on one file system and data on another. I think the way to handle moving data files to a new computer is to keep all your data including sessions under one directory tree so the whole thing can be easily copied. If instead the goal is to occassionally make a self-contained session then copying the map files and session file to a new directory would be a nice option similar to embedding all files in the session. I've noted this in the feature request for embedding the map files. http://plato.cgl.ucsf.edu/trac/chimera/ticket/9763 The sphere/axes display idea is one way to see the axes of a displayed model. The transparent sphere would cause problems in Chimera some of the time because Chimera can only correctly display one transparent model at a time. The current default is to show a single transparent layer, so any transparent model inside the sphere would disappear. This is a longstanding and hard problem to fix. But a mesh could work. Another idea is simply to depict the x,y,z axes. I've made a feature request for this. http://plato.cgl.ucsf.edu/trac/chimera/ticket/12062 Tom On May 8, 2013, at 12:25 AM, "Marlovits,Thomas" wrote: > Hi Tom, > > I do have a question related to saving sessions, which is a great option btw. > Is there a way that one can save the session - let's say in a new folder but then have all models also saved in there. For now, as I understand, it will only save the path/filename of those models. So, whenever we switch computers, hard-drives etc … this can turn out to be a lengthy process to find those models (we often have many models open at the same time). > Ideally, also fetched files from the pdb would be great to be saved locally in this new folder. > > The second question I have is related to turning molecules around specific x/y/z angles. > I'd love to have an option to display a big sphere that encapsulated the other models displayed. Ideally, this sphere would look like a globe with cordinates in there … if this is displayed at semi-transparency, one can easily go to a specific position but get more of an idea to easier naviagte through the 3D space. Sometimes I only would like to get a rough estimate about the angles to turn molecules. Alternatively a mesh-like grid could do the same job (and if one could display the numbers of the lattidude/longitude or so that would be great too). > > Many tx, > -T. > > > ------------------------------------------------------------------------------- > > Thomas C. Marlovits, PhD, M.A.S. > The MarlovitsLab @ IMP/IMBA > http://thomas.marlovits.myresearchlab.org > > Contact/Address/Directions: > http://thomas.marlovits.myresearchlab.org/lab/Contact.html >

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Define centroid issue
by Francesco Pietra 08 May '13

08 May '13

Hello: I was unable to put to work define centroid radius 0.5 color red :ligand_residue_name or define centroid radius 0.5 color red #0&@serialNumber=1972 with a homodimeric protein (I am at CHARMM NAMD/XPLOR, so that the two subunits are only distinguished by either the atom sequential number or the segment name, the latter not being understood by chimera, as far as I know). In the first case, running the movie after the appropriate further steps, the centroid sequence obtained was for the centroid between the two protein ligands, as it was expected. In the second case (as I wanted to refer to the ligand in subunit A only), the command raised the error: AttributeError: 'NoneType' object has no attribute 'openState' File "/opt/UCSF/Chimera64-1.7/share/StructMeasure/Geometry.py", line 293, in _getRefInfo invXForm = lowest.openState.xform Please notice that the line command #0&@serialNumber=1972 correctly selects the ligand on subunit A (a diatomic ligand, where "1972" is the sequential number of one of the two atoms of the ligand. Here "#0" may be redundant, as it deals of a single model. However, using "@serialNumber=1972" raised the same error. I fear I am missing some obvious facet of define centroid, so that I thank you for your patience. francesco pietra

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Question about measuring volume in chimera
by Varun Kumar 07 May '13

07 May '13

Hi, Can we outline a particular area and measure volume in chimera? I wish to measure specifically the purine binding site in the ATP binding pocket of Protein kinase C. Best regards -- Varun Kumar International Graduate Student School of Biomedical Sciences Department of Biological Sciences Kent State University, Kent, Ohio, U.S

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RMSD
by George Tzotzos 04 May '13

04 May '13

Hi everybody, I am trying to measure the RMSD between a docked ligand and the corresponding ligand in an X-ray structure. I've been looking to find a way of doing this in Chimera to no avail. I'd be grateful for any suggestions on how to do this. Best regards George

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save map with the adjusted threshold
by Moumita Dutta 01 May '13

01 May '13

Hello, I'm not sure if I can do this in chimera. Once I open a density map and adjust the threshold and removed dust how can I save the map in this setting so that next time when I open it I don't have to adjust again. Thanks

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Chimera shutsdown when opening sideview
by vamsee 29 Apr '13

29 Apr '13

Hi Elaine, I have recently moved to Linuxmint 14 from Windows 7. I can open virus capsids very easily (much more easier than in Windows 7, which is pretty sweet). But, every time I try to open the Side View option from the menu, Chimera shuts down. I have tried version 1.7 and 1.8rc. Both exhibit the same behavior. The interesting thing is, I can open all the other tabs (Effects, Lighting etc.) on that window from the menu. But when I click on Side View, Chimera crashes immediately with no bug report (Its almost like the process never existed). So, I tried starting chimera from the command line with the Side View option enabled (sudo chimera --start "Side View"). That started the Side View window and that stayed even after I opened my models. I then closed the Side View and re-opened it from the menu bar this time in the same chimera session. That worked again. So, I am kind of at a loss though I seem to have a work around for now. I have used the same features on Windows 7 (I still do using a virtual machine inside Linux) and they work fine. Any reason why this would happen? My computer specifications Processor : Intel® Core™ i7-2630QM CPU @ 2.00GHz × 8 Memory : 8Gb Onboard Video : Intel® Sandybridge Mobile OS : LinuxMint 14 Thank you Vamsee

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morph conformation
by Moumita Dutta 27 Apr '13

27 Apr '13

Hello chimera-users, I'm trying to use the option morph conformations from the command line and cannot specify more than one molecule with the command morph start. How to use the morph start command for more than two molecules ? Thanks for any help. Moumita

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morph map and movie recording
by Moumita Dutta 26 Apr '13

26 Apr '13

Hello, I am trying to morph more than two maps at a time so I am using vop morph instead of Morph map. I am following the mini-video animation example script of vop morph using the recommended chimera 1.7 version 2013. The script actually recorded the movie but in the movie threshold changed from what I set and it turned some maps to x 90 degree not all and it is not showing the morph animation only the superimposed maps. Another problem is though I remove the dust after loading the maps but it came back in the morph and in the movie as well. How can I fix the problems and generate the movie ? Moumita

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Ubuntu 12.10 and Chimera update #2
by Greg Couch 25 Apr '13

25 Apr '13

Found a better solution to Chimera's problems on Ubuntu 12.10 -- just install Ubuntu 13.04! HTH, Greg

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Re: [Chimera-users] movie recording from morph map
by Elaine Meng 25 Apr '13

25 Apr '13

On Apr 25, 2013, at 1:01 PM, "Moumita Dutta" <dutta(a)bio.fsu.edu> wrote: > Hi Elaine, > I am trying to morph more than two maps at a time so I am using vop morph instead of Morph map. I am following the mini-video animation example script of vop morph like below > > Record the movie > # > > movie record supersample 3 > > wait 1 > movie crossfade > vop morph #0,1 frames 200 > wait 200 > > movie encode morphmap.mp4 morphmap.webm morphmap.ogv bitrate 200. > > It starts recording the movie but it does not stop. > Best, > Moumita Hi Moumita, The first thing to check when following a tutorial or examples is your version of Chimera. The top of the mini-examples page <http://www.cgl.ucsf.edu/chimera/data/movie-howto-mar2012/movie_examples.html> says that they were made with Chimera version 1.7 from March 2012 or newer. In those versions, movie recording will automatically stop when you use "movie record." In older versions, you have to use the "movie stop" command to stop recording before you do the encoding. (I cc'd chimera-users(a)cgl.ucsf.edu -- please use that address for Chimera questions unless your data are private) I hope this helps, 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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Seeking guidance on Volume-volume fitting
by ingvar 25 Apr '13

25 Apr '13

Dear Chimera, I am seeking guidance on what would be best practice in doing volume-volume fitting, and what expectations should I have on number of trial conformations. For instance would it be beneficial to resample one of the volumes to the same grid as the other volume. What about volumes with different resolutions, do this require any special handling. In the case below it would probably be more efficient to just align the principal moments of inertia of the envelopes above the contour level and then do a search from there, though this will only work well if the volumes are very similar. In an initial study I used 3 EM volumes from EMDB, (EMD-5500, EMD-5501, and EMD-2017). They are all 30S E. coli ribosomes of similar resolution (12.9, 14.0, 13.5 Å). I thought that this would be a relatively easy starting point, with the intent to then go on to fit 30S subunit in some of the many E. coli 70S EM volumes that are available. The volumes EMD-5500 and EMD-5501 are in similar orientation, while EMD-2017 is in a completely different orientation. The grids are similar but not identical, 125^3 vs 128^3. I adjusted the contour levels from the EMDB recommended values to make the enclosed volumes more similar in size. Contour levels used: EMD-5500 -2.8 -> -2.5 EMD-5501 -2.8 EMD-2017 39 -> 32 I am using scripts like the one shown here: from chimera import runCommand as rc from chimera.tkgui import saveReplyLog rc("open data/EMD-5500.map") rc("volume #0 level -2.5 transparency 0.5") rc("open data/EMD-5501.map") rc("volume #1 level -2.8 transparency 0.5") rc("fitmap #1 #0 search 50000 metric cam envelope true inside 0.2") saveReplyLog(r'/Users/ingvar/chimera/log/fit5500_5501_loc.txt') It seems correlation about mean is the best metric for volume-volume fitting, and that it is best to only use points inside the envelope. The maps EMD-5500, and EMD-5501 have the unusual feature that the density range is shifted downwards so that the average is well below 0. I was concerned about that and moved the density range, but with the fitmap parameters above that did not seem to have any significant impact (with other sets of parameters the density range appears to be an issue). In this case, it is relatively easy to see when you have found the "good" fit, all other fits have clearly worse statistics. What I was surprised about was the number of trial conformations needed to be reasonable certain to find the "good" fit. 5500 in 5501 7 times in 5000 5501 in 5500 2 times in 5000 5500 in 2017 0 times in 5000 5500 in 2017 8 times in 50000 2017 in 5501 0 times in 5000 Many Thanks, Ingvar Lagerstedt

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morph map and molecule together
by Tom Goddard 24 Apr '13

24 Apr '13

Hi Moumita, You can morph both maps and molecules at the same time. You use commands instead of the morphing dialogs in order to get them to play with perfect synchronization. The basic plan is to create the molecule morph and the map morph using the dialogs as usual. Then load a simple command script that starts both playing at the same time and records the movie. I'm sure this works in Chimera 1.7, probably in 1.6, and maybe in 1.5. Here is an example command script morphing a filament map and fit molecule http://www.cgl.ucsf.edu/chimera/data/santa-cruz-aug2012/scripts/movie2.txt and here's the resulting movie http://www.cgl.ucsf.edu/chimera/data/santa-cruz-aug2012/images/morph1.mp4 and here is the web page where I explain how this was done http://www.cgl.ucsf.edu/chimera/data/santa-cruz-aug2012/animate.html This was a demonstration I gave at the Bay Area Cryo EM meeting in Santa Cruz last summer. Tom -------- Original Message -------- Subject: morph map From: Moumita Dutta To: goddard Date: 4/23/13 10:16 PM > Hi Tom, > > I want to morph a set of density maps and the atomic models fitted > into them together and run the two movies concurrently so that I get a > movie that shows how the density and the atomic models change > together. I have been able to make the two different sets of data > morph independently, but thought it more informative if they morphed > together. > > I was wondering whether this can be done using chimera ? If so which > version supports it ? > > Thanks, > Moumita > > >

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Hide bonds
by Masaki Uchida 23 Apr '13

23 Apr '13

Dear Chimera users Is it possible to hide bonds between spheres (atoms/bonds view)? I have a "pdb" file which is a bead model of a protein generated by SAXS analysis. When I open the file and changed a view to "sphere" under "atoms/bonds", bonds between beads are shown. I believe the bonds are meaningless in this case and would like to show just spheres (beads). Thank you in advance for your help -- ********************************************** Masaki Uchida Department of Chemistry&Biochemistry Montana State University **********************************************

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dock
by LW 23 Apr '13

23 Apr '13

Dear all, As attached, I have a structure of Saposin C in the presence of SDS micelle solved using NMR. I took the first model out of its 20-structure ensemble and generated SapC_one_model.pdb. I also have a PDB file(as attached )built to model SDS micelle surrounded by water. Does Chimera allow people to dock these two molecules and generate a combined PDB file for further analysis? While the structure of Saposin C in the presence of SDS micelle, NMR data indicate that the open hydrophobic core is in contact with SDS micelle. Is it possible to use Chimera to determine the relative orientation of the two molecules where (i), they are in intimate contact, (ii), there is no clash, (iii), the shape complementarity is at its optimal? Any clue would be much appreciated. Levi

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batch production of images
by Benjamin SCHWARZ 23 Apr '13

23 Apr '13

Dear list, I am considering to use chimera to render (a tons of) pictures of models that I generated and issued in nice markerSet (.cmm) files. 1. If I understand well, the only way to do that is through the linux headless version, and there is no way to do that under MacOS X for the moment 2. I should then use the "copy" command. Something like : chimera --nogui --script "myscript.py" where myscript.py should contain something like "from chimera import runCommand; runCommand('copy file pipo.png')" 3. All my models were produced in a same cartesian, and I'd like to keep the orientation and "picture frame" similar for all pictures. What I mean here, is that I'd like to be able to set my camera somewhere, looking in a specified direction, which I would probably do under the chimera GUI; and then, shoot all my pictures from that point of view on a batch mode. How shall I do that (set a point of view for the camera and use it on a batchmode) ? Thanks a lot again for your great job, and your constant answers --Ben

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stereo viewing with consumer graphics cards
by Greg Couch 22 Apr '13

22 Apr '13

In the past, Chimera has always needed a workstation-class graphics card (e.g., AMD FirePro or NVIDIA Quadro) to view molecules in 3D stereo and read dialogs at the same time. Now that there are 3D HDTVs, that has changed. I have just confirmed that with a computer running Microsoft Windows 8, with an AMD Radeon HD 7850 graphics card, and a Panasonic 3D HDTV, that 3D stereo worked without fiddling with any display settings. That is awesome -- "without fiddling with any display settings". Windows 8 is a requirement, Windows 7 will not work. I am unaware of any effort to get Linux to work. There is a good chance that Apple Mac OS X will work and we plan to test that soon. Any recent AMD Radeon HD graphics card with HD3D, or NVIDIA GeForce graphics card with 3D Vision support, should work. I hope to test a NVIDIA graphics card soon to confirm that. And supposedly, any 3D HDTV will work. The 3D HDTV in the test was a Panasonic TC-P50GT25, from 2010/2011, and I expect that any 3D HDTV that support a full resolution stereoscopic 3D format will work well. Non-full resolution formats would work for the 3D stereo images, but the associated 2D dialogs would be unreadable. Happy 3D viewing! Greg

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Distance between atoms at the interface
by Mehdi Talebzadeh Farooji 22 Apr '13

22 Apr '13

Dear Chimera Users, I was wondering if there is a way to show distances between two objects (two chains) and filter them; for instance to display all of the distnaces between atomes of two interacting protein chains which are less than 6 A. Any help would be much appreciated, Mehdi

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View Dock plugin
by James Starlight 22 Apr '13

22 Apr '13

Dear Chimera users! I have a question about the View Dock plugin. >From some servers usually I've obtained pdb file of the target protein as well as separate file consisted of all predicted posses which I can visualize in Chimera. So I wounder to know 1- How I could hide hydrogen bonds as well as protein's side chains of the residues which are in contact with the ligands ( on the default both of that two options are turned ON) 2- How I could properly save some poses as the separate pdb models ? E.g when I chose to same target.pdb with the #1_pose from the chimera saving menu I obtain protein and ligand with the surrounded residues as two models in one pdb file ( so I must manually merge it in one model and delete residues from the second model). Does it possible to obtain protein-ligand complex as one model as the output? Thanks for help, James

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multiple volumes' orientation in space
by Yunji Wu 22 Apr '13

22 Apr '13

Dear all -- I am a total newb to Chimera, and I have an issue which I feel like can be easily resolved with your help. I am trying to make a 'structure-based schematic' with the purpose of clarifying the locations of the domains of a complicated crystal structure. There are 12 domains in this structure that I want to represent as 'blobs', and they are oriented in space in a very confusing way, especially if represented as the standard ribbons or cartoons. I used pdb2mrc (in EMAN2) to create 25Å maps from my .pdb files for (with the command e2pdb2mrc.py -R 25 H.pdb K.mrc). These show up fine individually in Chimera, but the separate maps are not oriented properly in space. It looks like the map volume files have no instructions about where to be in space relative to the coordinate files that generated them. If I take a single .pdb file with all 4 chains and generate a single .mrc file, I obviously get something that has the chains correctly oriented. This is less useful and satisfying, since I'd like to make separate chains into separate map volumes so I can color them separately (for example: chains H,K,L,M as H.pdb, K.pdb, L.pdb, M.pdb into H.mrc, K.mrc, L.mrc, M.mrc). When these 4 volumes are plotted in Chimera, they appear to be semi-randomly piled in the middle of the viewing field, with no correlation to the original pdb coordinates (attached screenshot of volumes from 4 chains, calculated from 4 individual pdb files). Is this just a result of a preset in Chimera that I am not aware of that needs to be adjusted? If I plot the original pdb file with the 4 chains from which these volumes were generated, there is no spatial correlation between the structure and the volumes. In trying to solve this, I know that "Fit to Map" will allow the coordinates to be fit into the map volume, but I cannot seem to fit the separately map to the individual chains, which would be a longer way around the issue. Is there some way to do this, or to just create maps that are oriented properly in space relative to each other? Thank you so much for your help, Yunji Wu

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Radius of gyratiion
by George Tzotzos 22 Apr '13

22 Apr '13

Hi everybody, I've search the archive to find a script for measure protein radius of gyration. I came across the following link: http://plato.cgl.ucsf.edu/pipermail/chimera-users/2012-February/007257.html I'm now trying to find the actual script <radius-of-gyration.py>. Any ideas how to retrieve it? Many thanks in advance George

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euler angle
by Jingchuan Sun 19 Apr '13

19 Apr '13

Hi, After I rotate a volume to a specific orientation, and "save map as" in "volume viewer", the saved volume are still in the original orientation. Could I save it in the new orientation. If I could display the current euler angles, I can rotate it in other software. But how could I display euler angle after rotation? Thanks! Jim

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Doubt
by Víctor J. Gallardo López 19 Apr '13

19 Apr '13

Good Morning Mr./Ms., I have a bit problem with the molecular modeling. I have a dímer (the two chains of this protein are the same sequence) and I want to put 34 residues at the N-terminal in each chain. I load my fasta (with this residues addition) in chimera and I blast a protein structure in the PDB that has the same residues as my protein without this addition. When I modeller (homology) my fasta, the programm only gives me one of the chain with this addition but I need the whole protein (with the two chains and with this residue addition for each chain as well). How can I do it? I hope you resolve my problems. Thanks you for you attention. Sincerely, Víctor J. Gallardo

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Generating trajectory of a user-defined plane
by Lili Peng 18 Apr '13

18 Apr '13

Hi, I am interested in measuring the deviation of an helical segment with respect to the initial structure in a GROMACS trajectory. I have already uploaded my *.tpr and *.trr files into MD Movie and have defined a plane through the helical segment within the initial structure. Is it possible to define another plane through the same helix and track the intersection angle throughout the trajectory? Thank you, Lili

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