- Chimera-users - RBVI Mailing Lists

Re: [Chimera-users] defining a putative binding site
by Elaine Meng 18 Feb '09

18 Feb '09

Hi Francesco, If you want detailed information about which atoms contact which, and the distances between them, use the "Find Clashes/Contacts" tool, or its command version "findclash", as discussed in several previous posts: <http://www.cgl.ucsf.edu/pipermail/chimera-users/2008-November/ 003260.html> <http://www.cgl.ucsf.edu/pipermail/chimera-users/2008-October/ 003163.html> <http://www.cgl.ucsf.edu/pipermail/chimera-users/2008-October/ 003183.html> There are links in those posts to the manual pages and a tutorial with an example. Some of those discussions were about finding contacts for a ligand, but the findclash feature is general and can be used on whatever set of atoms/residues you want. Again, you can save results to a file or write them to the Reply Log. Best, Elaine ----- Elaine C. Meng, Ph.D. meng(a)cgl.ucsf.edu UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html On Feb 18, 2009, at 10:55 AM, Francesco Pietra wrote: > Hi Elaine: > > By doing as indicate in your and my post, only residues (45 residues) > for model 0 (the bigger protein) are listed. Then I also commanded: > > sel #1:1701-1793 & 0:20,30-40,55 z<5 > > i.e., inverting the order of the two models. That gave a list of > residues (18 residues) for only model 1 (the smaller protein). > > Probably all that is useful information. But, is any way (one touch, > as above) to get information about which-to-which? > > I am not too lazy, I am prepared on the basis of the above two > listings, to use the zone command residue per residue, should this be > the way. > > (the numbers for the above residues are just for a split example; > actually I set all residues - even for areas that I knoe are not > involved - in the zone command for both proteins) > > Thanks > francesco >

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defining a putative binding site
by Francesco Pietra 18 Feb '09

18 Feb '09

Hi: I need to define a putative binding site for a smaller protein upon a larger one. The task is creating a table of likely interactions between residues of the larger proteinseparated by less than 5 A from those of the smaller protein. Deriving from molecular dynamics, all residues for both proteins are in the same pdb file, alongside lipid, water, etc. I wonder whether the most appropriate way is to separate in two different pdb files the lines belonging to the two different proteins. Then: sel #0:20,30-40,55 & #1:1701-1793 z<5 where "0" is the larger and "1" is the smaller protein. If OK, can the results be obtained in a table form? Thanks francesco pietra

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Re: [Chimera-users] color changes
by Elaine Meng 17 Feb '09

17 Feb '09

On Feb 17, 2009, at 1:15 PM, Jean-Paul Armache wrote: > hello, > i have one question concerning color manipulation in chimera. > every pdb file one opens gets a specific color (if set so). so, > having a few of them open, one can distinguish > between them color-wise. > now, when one selects the files, it is possible to change the color > via actions->color. this indeed changes all > of the things selected, and if the whole pdb was selected, all the > chains there. when one looks then into the > model panel, the old colors are still there - untouched. this would > be reasonable in the case when only parts > of the pdb were selected and re-colored. however if one selects > whole files and changes the colors - is it > possible to have these colors changed also in the model panel? and > is it possible to revert to the old color > once changed through this action menu? > > best regards, > jean-paul armache Hi Jean-Paul, It is because there is a coloring hierarchy: the Model Panel shows the model color, but you can also set atom colors, whichoverrule and hide the model color. As you found, Actions... Color and the "color" command set the atom colors (otherwise you would not be able to make different parts of the same model different colors). If you already colored the atoms of a model, you can "uncolor" some or all of them to reveal the model color using the command "~color". Another way is to choose "Actions... Color... from editor" and then click the "No Color" button in the Color Editor. (The Color Editor can be found in the menu under Tools... Utilities) You can change the model color with the command "modelcolor" or by clicking on the square color wells in the Model Panel to call up the Color Editor. <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/coloring.html> <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/hierarchy.html> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. meng(a)cgl.ucsf.edu UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html

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surface view of large file in chimera
by G.-Q. Hu 17 Feb '09

17 Feb '09

Hello, I am trying to show a large file by surface view in chimera. But I found that the structure lost the detail and the surface was smoothed. I guess there is a sampling problem for large file. Is there any way to view the large file at the original resolution? Thanks. Guiqing

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Volume->Fit in Map question
by Keren Lasker 17 Feb '09

17 Feb '09

hello, Is there a way to fit a density map to a pdb rather than a pdb to a density map ? Or in other words, that in the end of the fitting procedure the map would move to best fit the model rather than the other way around. thank you, Keren Lasker.

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configuration file for chimera
by Bala subramanian 17 Feb '09

17 Feb '09

Dear chimerians, Sorry if this question has been asked before. Where can i fix the default parameters for chimera. I explored the preferences option in favourites menu and set chose some preferences. In addition to that I want to the following like setting the color of carbon atoms as green as default setting the color of hydrogen atoms as white as default setting some macros setting the command line option when the chimera starts up (every time i go to favourites and click command line to invoke it) and other settings something like the configuration file used for vmd (.vmdrc ). Thanks in advance, Bala

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stereo view
by Francesco Pietra 16 Feb '09

16 Feb '09

Hi: I would greatly appreciate advice about the following requests (between "".."") by the referees (interaction between two proteins; graphics by chimera): 1) "there is way too much wasted black space in figures". As the complex of proteins is elongated along one axis, I found it unavoidable to have wasted space around. Perhaps using a white background in the hope that white is less offending than black? Or is it a way to tailor the background according to the shape of the object? 2) "a stereoview might be helpful for better understanding". How to fulfill this request with chimera I have no idea. 3) "a molecular surface representation of the docking site would be useful". I read on passing about molecular surfaces on this forum. Is that feasible for the highly complex situation of 3D perspective with so many atoms at different "layers"? Thanks indeed for answering francesco pietra

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Consurf .chimerax file under linux
by Boaz Shaanan 16 Feb '09

16 Feb '09

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Re: [Chimera-users] Chimera 3D labels
by Elaine Meng 16 Feb '09

16 Feb '09

On Feb 16, 2009, at 6:53 AM, nettles wrote: > > Dear Elaine, > I'm thinking this should be possible, but don't know how to do it. > Can the labeling function in Chimera could be made more spacially > flexible? > > An example is below. The residue label coordinates are anchored to > a fixed 3D point that may, or may not be desirable for a given > view. Can this be adjusted? > > It looks like these references may be set at centroids. Maybe one > could have a toggle switch that sets the anchor projected a certain > distance from a C-alpha along the viewing vector. That might give > quick access unified text float-over > > Thanks again for such a great tool. > Jim [attachment removed by Elaine] Dear Jim, I am frequently irked by the same issue. Currently residue labels are anchored at the centroid of the displayed atoms, whereas sometimes it would look better if they were anchored at the alpha- carbon. I've previously created a bug report about this. Longer term we would also like them to be movable with the mouse, but that also can't be done currently. Here is the bug/request tracking info: http://socrates2.cgl.ucsf.edu/trac/chimera/ticket/6866 http://socrates2.cgl.ucsf.edu/trac/chimera/ticket/167 One current workaround is that you can label some particular atom in the residue with residue information. However, currently that atom must be explicitly displayed (won't work to label some backbone atom if ribbon is shown and suppresses that atom... which I've also complained about!). Commands to do that: labelopt info residue la @ca [or if ribbon is shown, "la @cb" instead if you can live without the glycine residue labels] I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. meng(a)cgl.ucsf.edu UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html

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Animating a C-alpha chain trace
by Tom Goddard 13 Feb '09

13 Feb '09

Hi Matt, A Python script can make a chain trace movie with density display that adds one residue at a time. I've attached an example script and movie. I used the today's Chimera daily build that has a nice 1-layer transparency option. That won't work in earlier Chimera versions. Tom Matthew Dougherty wrote: > Hi Tom, > > Over the last couple years I have moved my animation off the > SGI/IrisExplorer to Chimera/Amira. > > I have one piece of code on Explorer that I have not moved; attached > is a typical animation. > > what is being accomplished is a demonstration of the folding of a > protein based on c-alpha backbone and related density. > starting at the first residue, it proceeds by adding one residue at a > time. > > How would you suggest to move this to chimera? > > Matt > > > > > > > > > > > > > > > # ----------------------------------------------------------------------------- # Trace C-alpha backbone adding one residue at a time and show simulated map. # pdb_path = '/usr/local/src/staff/goddard/pdb/pdb1fav.ent' resolution = 5.0 # Simulated density resolution, Angstroms map_color = (.6,.7,.8,.3) # red,green,blue,opacity. from chimera import runCommand # Open model from chimera import openModels as om m = om.open(pdb_path, 'PDB')[0] # Orient molecule runCommand('turn y 90') runCommand('turn x 30') # Color molecule and background runCommand('rainbow') runCommand('set bg_color white') # Create residue number label runCommand('2dlabel create rlab xpos 0.1 ypos 0.9') # Set display style. runCommand('repr stick #%d' % m.id) m.stickScale = 5.0 # Fatter sticks # Order residues by number and chain id. rlist = m.residues rlist.sort(key = lambda r: (r.id.position, r.id.chainId)) # Hide all atoms. for a in m.atoms: a.display = False # Show density adding one residue at a time. from MoleculeMap import molecule_map atoms = [] map = None for r in rlist: # Accumulate atoms from residue. atoms.extend(r.atoms) # Close previous map. if map: om.close([map]) # Make map. map = molecule_map(atoms, resolution, gridSpacing = .2*resolution, showDialog = False) map.set_parameters(surface_colors = [map_color], one_transparent_layer = True) map.show() # Display backbone atoms. for a in r.atoms: if a.name == 'CA': a.display = True # Update residue label text = 'chain %s residue %d' % (r.id.chainId, r.id.position) if r.isHelix: text += ' helix' elif r.isSheet: text += ' sheet' runCommand('2dlabel change rlab text "%s" color black' % text) # Draw one frame. runCommand('wait 1')

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Re: [Chimera-users] Command Line - Slecting Zone Parameters
by Elaine Meng 11 Feb '09

11 Feb '09

On Feb 11, 2009, at 2:54 PM, Thiruvarangan Ramaraj wrote: > Hi all, > I am trying to find all the atoms that lie within a certain > distance from a selected chains. I am able to do this by going to > select -> zone and giving the distance I want and selecting all the > atoms that met my criteria. I would like to do this on command > line. I am unable to figure it out. > Any help would be greatly appreciated. > Thank You > Thiru Ramaraj Hi Thiru, The following command would select all residues with any atom within 4.5 angstroms of your current selection: select sel z<4.5 You could use "za" instead of "z" if you want an atom-based cutoff instead of whole residues, > instead of < to get the atoms farther away, and of course, a different distance. Also, you don't have to use selections. For example, this would color all atoms within 5 angstroms of chain A red: color red :.a za<5 Description of command-line zone specification: <http://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/midas/ atom_spec.html#zones> More examples appear in various tutorials: <http://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/tutorials/ attributes.html#part2> <http://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/tutorials/ squalene.html#surfaces> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. meng(a)cgl.ucsf.edu UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html

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maps handling
by Benoit Zuber 11 Feb '09

11 Feb '09

Hi, I want to handle a large number of small density maps (around 1000 maps of approx 50x50x50 pixels). I need to group them (in around 5 groups). Then I need to treat all the maps of each group in a certain way. For example, I would like to change the level threshold for display, or the display style for every maps in a group at once. Also I would like to show or hide all maps of a group at once. The maps are not opened in an order related to their group. I remember someone recently suggested model 'folders' as a new functionality. Has this been incorporated in the latest versions of chimera? Even if it is the case, It would be too tedious to have to click on each individual model to assign it to a group. Similarly a simple command passed at the command line wouldn't be very elegant: I would have to write each volume number since they are unsorted. I suppose a python script would be much more appropriate. The script would have some functions to do tasks like those described above on each members of a group and a function to read group composition from a text file. I looked in chimera's programmer guide for a section on volume handling but I couldn't find much material on that. Did I miss it? What approach would you recommend? I guess I could use runCommand() but there are maybe better ways. Also the script would have to run in interactive mode. I suppose that IDLE would work for that purpose. How should I do that? Open IDLE and import my module? Where can you define the paths that chimera uses to look for packages? Thanks in advance! Ben -- Benoît Zuber MRC Laboratory of Molecular Biology Hills Road Cambridge CB2 0QH United Kingdom +44 1223 402209 bzuber(a)mrc-lmb.cam.ac.uk

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examples of python scripts
by Bala subramanian 11 Feb '09

11 Feb '09

Dear Chimerians, Can someone help me by providing examples of python scripts written for analyzing structures inside chimera. I have seen the chimera programmers guide but i need some more scripts written for different tasks to understand the way of accessing certain residues or atoms in a structure and extracting its attributes etc. Cheers, Bala

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making movies with CMM files
by Keren Lasker 06 Feb '09

06 Feb '09

hello, Is there a way to generate a movie out of a set of CMM files ( similar to MD Movie with PDB files)? thank you very much, Keren.

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Re: [Chimera-users] [chimera-dev] alias menu
by Eric Pettersen 05 Feb '09

05 Feb '09

On Feb 4, 2009, at 5:09 AM, Richmond Timothy J. wrote: > Dear Chimera Developers, > > Perhaps I have missed it, but I would find a menu for selected > aliases very useful. Having returned to Chimera from PyMol recently, > it would be great to have an option for the alias command that > allowed the particular alias to be listed in a separate window and > ran the alias by clicking on the alias name listed there. > > Best regards, > > Tim Hi Tim, As Elaine pointed out in her reply, aliases are frequently used as shorthands for long atom specs rather than as replacements for complete commands. However, the form of the alias command that uses '^' (so that matching only occurs at the start of the line) typically is used to define full command aliases. So my thinking is this: aliases defined with the '^' character would be placed in an 'Aliases' top-level menu (created on the fly as needed). Such aliases would automatically be remembered across Chimera invocations (and populate an Aliases menu). The menu could be torn-off (except on Aqua) to make a stand-alone window. Those aliases could be deleted as normal with the ~alias command (which would remove them from the menu and no longer remember then in subsequent Chimeras). Would this be good enough? --Eric Eric Pettersen UCSF Computer Graphics Lab http://www.cgl.ucsf.edu

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script command for writing out areaSAS attribute?
by Julius Su 05 Feb '09

05 Feb '09

Hello, Does anyone know what script command could be used to output an "attribute assignment file" in Chimera, specifically for the areaSAS attribute? I am trying to show how the solvent accessible surface area on various residues changes over the frames of a multitrajectory PDB file. To do this I am trying to write a small script in "MD movie" that computes the solvent accessible surface for each frame, then outputs the areaSAS values. I was previously able to do this by loading in all the PDB geometries at once, then using the "Render attributes by ..." dialog, but this method does not scale well to very large proteins (the program runs out of memory trying to compute all the surfaces at once). Thus I am trying to do this task sequentially with a script. Thanks much! Julius

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Is it possible?
by Ahir Utsav Pushpanath 04 Feb '09

04 Feb '09

Hello Dear Sir/Madam, I am very fond of chimera, and everytime I have looked at scripts for doign things, I find that chimera has them already inbuilt as features. There is one particular problem that I am sure chimera has the capability of doing but I am struggling to do it. 1) I want to use structural superposition servers such as Mammoth etc to produce a structural alignment of two proteins, 2nadA and 1ybaB. However, some of these servers do not produce a sequence alignment output in a format compatible with chimera (i.e such as .aln or aligned fasta). But they do produce a .pdb file showing the superposition. 2) If I load the .pdb onto chimera, sometimes in "model list" window, i see the two proteins, wheras in others I only see 1 model(yet there is clearly 2 models there) 3) I was wondering whether you can load the superposition onto chimera, and see the sequence alignment that gives rise to that structural superposition, so that I may save it as a .aln format using multialign viewer. How do I do this? Apologies if this is a very straightforward scenario. Thanks Ahir

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roll command:
by Bui Khanh Huy 01 Feb '09

01 Feb '09

Dear all, I tried the roll command with my model (EM map) open: roll z 30 1 center 50,50,50 Chimera showed msg "wait_frames argument not implemented". Just wonder how to implement that command without the error? Huy

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Calc buried surface area between 2 chains
by Tom Duncan 30 Jan '09

30 Jan '09

I saw an earlier post (Dec. 29, 2008; Digest vol. 68, issue 28) in which Elaine Meng described a procedure for calculating surface area for selected atoms. I did this for atoms on chain A that were selected as contacting atoms on neighboring chain B, but the sum(atom.areaSES) probably includes area buried within the chain A, not just between the 2 chains. I tried checking this by calculating the sum(atom.areaSES) for chain A (all atoms in A) in the whole model, then again for a model from which chain B was deleted before calculating the surface. However, the results indicated a larger areaSES for chain A in the absence of chain B! There were some errors reported in calculating the surfaces; perhaps this contributed. Is there a better way to calculate the buried surface on 1 chain due to contacts with a 2nd chain? Thanks, Tom Duncan

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error message
by Katherine Parra 28 Jan '09

28 Jan '09

Hello! I'm trying to get the hydrogen bonds between some selected residues during a trajectory, using per frame commands from tools. But when I get the possible hydrogen bonds formed between the selected residues I also get the following error message in the Reply Log: *Skipping possible acceptor with bad geometry: #0:2108@O Wrong number of grandchild atoms for phi/psi acceptor #0:2108@O *What could be happening? Thank you in advance. KP

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color zone on command line
by Giulia Zanetti 28 Jan '09

28 Jan '09

Hi all, I would like to make a movie in which areas of my map are coloured while the surface is rotating. Any idea how to use color zone from the command line? thanks Giulia

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fit in map output : coordinate representation of axis, axis point
by Hwang, Youngha,Ph.D. 27 Jan '09

27 Jan '09

Hi, could anyone explain to me what axis points mean in chimera? What unit is used for them? Is it related to the volume dimension? Is the rotation matrix based on Euler-angle representation? Thanks, Youngha. The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.

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3D on Chimera.
by ayassin＠wadsworth.org 27 Jan '09

27 Jan '09

Hello, I am trying to use Chimera to model pdb files into EM maps. When I select the red cyan stereo, the EM map is stereo but the pdb structure is not. -Is there anyway to display pdb in stereo in Chimera, how? -Is there another program that would allow me to do the same thing: fit pdb in EM density map-in stereo(other than "O")? -When I use Chimera on windows VISTA the side view panel does not appear and a message about graphic card appear, anyway to solve this? Thank you all very much. Aymen Yassin. Postdoc Research Affiliate Wadsworth Center, Albany,NY. IMPORTANT NOTICE: This e-mail and any attachments may contain confidential or sensitive information which is, or may be, legally privileged or otherwise protected by law from further disclosure. It is intended only for the addressee. If you received this in error or from someone who was not authorized to send it to you, please do not distribute, copy or use it or any attachments. Please notify the sender immediately by reply e-mail and delete this from your system. Thank you for your cooperation.

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marker coordinates
by Gabor Papai 27 Jan '09

27 Jan '09

Hi, I would like to do the following: I placed markers on density spots. I want to get their coordinates and excise a box around the marked density and save it as a separate file. For this I would like to know how I can retrieve the coordinates of a marker set and possibly how to position exactly a box around a marker to set a subregion (and of course how to set the dimensions of that box). This second feature existed before, but disappeared in the latest releases with the subregion selection tool in the Volume Viewer. Thanks in advance, Gabor -- Gabor Papai IGBMC Department of Structural Biology and Genomics 1, rue Laurent Fries, BP 10142 67404 Illkirch, France phone +33-3-88655748 Fax +33-3-88653201 E-mail: papai(a)igbmc.u-strasbg.fr

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Volume information
by vamsee 26 Jan '09

26 Jan '09

Hello All, I am working on a virus and I am trying to figure out its volume. I would want to find out the volume of the nucleic acid and the water inside the virus capsid. That way, if I am thinking right, that should give me the total internal volume of the virus. This volume would be a constant even with the movement of water in and out. Is it possible to use chimera to calculate any of such data, with no prior information about how the nucleic acid is packed inside? Thanks in advance, Vamsee Graduate Student Dept of Chemistry and Biochemistry Montana State University Bozeman, MT - 59715

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