May 2007 - Chimera-users - RBVI Mailing Lists

Tips for making density map images.
by Thomas Goddard 21 May '07

21 May '07

Here are some suggestions for making density map images in Chimera 1.2382. White background color. Set with two menu entries Actions/Color/Background and Actions/Color/White. To make white the default use Favorites/Preferences, category Background, set background color button to white and press Preferences dialog Save button. Surface smoothing. Use volume dialog Features/Surface-And-Mesh-Options and click "Surface smoothing..." checkbutton. To make this the default, turn it on then use Features/Save-default-dialog-settings. Close the surface-and-mesh-options panel before saving the settings or it will always be shown taking up alot of space. Image supersampling. Removes saw-tooth edges from saved images that are especially visible with white background. Does this by making a larger image in memory then averaging down to a smaller size. When saving an image you see many small pieces flash by in main window if supersampling is being used. To turn it on use File/Save-image, press the Image Setup button in the save image dialog, then set Supersample to 3x3 in the preferences dialog that appears. Press the Save button in the preferences dialog to make this the default. For Chimera versions after 1.2392 this will look different. Supersample will be an option on the save image dialog. Saving image same size as on screen. To make a saved image the same size in pixels as it appears in the Chimera window press the Get Pixels button in the File/Save-image dialog. In Chimera versions after 1.2392 this will be the default. Silhouette edges. To add black edges around maps that makes it easier to see when part of map is in front of another part use Favorites/Side-view, choose the Effects tab in the viewing dialog that appears, click on silhouette edges. Save raytraced image. Gives glossy appearance and shadows. Use File/Save-image and set "Raytrace with POV-Ray" to True. Make back parts of surface darker. Use Favorites/Side-view and move the right vertical yellow line towards the left. The surface gets dimmer from half way between the yellow lines to the right yellow line. Your eye position in this side view is shown as the square at the left and the red lines indicate how wide your field of view is. If you move the right yellow line (rear clipping plane) it will hide parts of the map -- everything to its right is invisible. Probably want to avoid that. Make recesses in surfaces darker to improve sense of depth. Use Tools/Volume-data/Surface-color. For spherical virus color the surface using "Radius", use 2 colors, Gray pattern, press "Set full range colormap values" to get minimum and maximum surface radius, press Color. You may need to press the Center button if the virus map is not centered at (0,0,0), and also press the "Set full range..." button again in that case. Probably you'll want to modify the minimum and maximum radius to get the best effect, also maybe adjust the two colors. For filaments use "Cylinder radius". Make recesses darker for asymmetric maps. This is a bit trickier than for spherical or cylindrical maps. For ribosomes or other asymmetric maps first create a blurred version of the map using Tools/Volume-data/Gaussian-filter. This tool has to be downloaded separately from the Chimera experimental features web page http://www.cgl.ucsf.edu/chimera/experimental/experimental.html and installed. Choose a gaussian width of about 1/3 the diameter of the surface (in angstroms, maybe 30 for a ribosome) and press Filter. Use the Tools/Volume-data/Surface-color and color the original map using the gaussian smoothed map. High values of the Gaussian smoothed map are in the interior and should be made a dark color. This makes the perception of depth dramatically better. Tom

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Re: [Chimera-users] [chimera-dev] Protein to ligand shortest distances?
by Elaine Meng 21 May '07

21 May '07

Hi Kate, The Find Clashes/Contacts tool will report all atoms near your ligand and the corresponding distances. However, it does not work with a single strict cutoff, but instead uses the atoms' VDW radii. For example, if you used a cutoff of 0.0 overlap, that would find all atoms with VDW surfaces either intersecting or just touching. It finds all the atoms meeting your specified cutoff criteria, so you would still need to look at the list of results to see which atom is the closest from each residue. There are two cutoff parameters, the amount of VDW overlap and the extra closeness allowed for H-bonding pairs. As mentioned in the manual page, http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/findclash/ findclash.html the suggested values for these two parameters are: 0.4-1.0 and 0.2-0.6, respectively, if you only want to detect "clashes" (unfavorably close contacts) -0.4-1.0 (negative values) and 0.0, respectively, to detect contacts in general It sounds like you want the latter. Select your ligand (for example by Ctrl-click on one atom and then hitting the keyboard up arrow), open the tool (Tools... Structure Analysis... Find Clashes/Contacts), click "Designate" to specify you want to find contacts of the selected atoms (the ligand) versus all other atoms. Set the parameters to -0.5 and 0.0. In the bottom section check "Write information to reply log" and uncheck the other options. Open the reply log (it's in the Favorites menu). Click Apply and the list of results will be written in the Reply Log window. You could play around with the VDW overlap parameter and when you think you have what you want, you could use the "Write information to file" instead of the reply log. As I mentioned above, you would still have to look through the results to see the closest atom from each residue. The more negative the parameter, the more atoms will be found (including those which are further away from the ligand). There is also a command version of this tool, http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/findclash.html If you really care that you include all residues with any atom within 5 angstroms, you could do an additional step first: select the ligand, then Select... Zone using 5 angstroms, then use Actions... Write List to save the names of the "selected residues" to a file. You can compare this list to the more detailed results from Find Clashes/Contacts to find the closest atom from each of the residues. I hope this helps, Elaine p.s. I'm sending this to chimera-users too because that is more for user questions, while chimera-dev is more for developer/programmer questions ----- Elaine C. Meng, Ph.D. meng(a)cgl.ucsf.edu UCSF Computer Graphics Lab and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html On May 20, 2007, at 10:12 PM, khar6039(a)mail.usyd.edu.au wrote: > Hi all, > I'm new to chimera and would like a simple way to zone 5 Angstroms > around a > ligand and then have chimera tell me what the shortest distances are > between these residues and the ligand. Is this possible? > Cheers, > Kate

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Multiple stucture comparision
by Pankaj Barah 19 May '07

19 May '07

Dear all, I have been using UCSF Chimera for structural superpositions for last few days. But while trying to do multiple superimposition for a set of proteins, i am unable to perform it. can anybody give me any suggestion? Regards Pankaj Barah Junior Research Fellow, Phone:+91-9922346120(M) Bioinformatics Centre, +91-20-25692039(O) University of Pune, Pune 411 007,Maharashtra, India. Pankaj Borah MSc Bioinformatics Univ of Madras(HCAS) Mobile number: 09884270481(Chennai)/ 09844514157(B'lore) Home number:(03752)259201 Alt. Mail id: pankajborah(a)gmail.com Group homepage: http://groups.yahoo.com/group/bioinformatrix/ --------------------------------- Office firewalls, cyber cafes, college labs, don't allow you to download CHAT? Here's a solution!

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Pub3D database URL
by Elaine Meng 18 May '07

18 May '07

Hi everybody, In a previous message I mentioned Pub3D as a useful source of 3D coordinates (SDF files) for many PubChem entries. The URL for that server is now http://www.chembiogrid.org/cheminfo/p3d Enjoy! Elaine ----- Elaine C. Meng, Ph.D. meng(a)cgl.ucsf.edu UCSF Computer Graphics Lab and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html Begin forwarded message: > From: Rajarshi Guha <rguha(a)indiana.edu> > Date: May 17, 2007 4:44:53 PM PDT > To: Elaine Meng <meng(a)cgl.ucsf.edu> > Subject: Re: Pub3D SDFs > >> I noticed that your Pub3D site has not been reachable for a while. >> ( http://rguha.ath.cx/~rguha/p3d/ ) > > Aah! My Apache redirect failed again :( > > Actually, we have a new URL for it which should be constant (and is > independent of my machine) > > http://www.chembiogrid.org/cheminfo/p3d > > ------------------------------------------------------------------- > Rajarshi Guha <rguha(a)indiana.edu> > GPG Fingerprint: 0CCA 8EE2 2EEB 25E2 AB04 06F7 1BB9 E634 9B87 56EE > -------------------------------------------------------------------

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mac stereo
by Dougherty, Matthew T. 14 May '07

14 May '07

what is the status of mac quadro fx4500 stereographics on chimera? thanks, matt Matthew Dougherty *** 713-433-3849 *** National Center for Macromolecular Imaging***

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benchmark
by Dougherty, Matthew T. 14 May '07

14 May '07

nvidia quadro fx 4500 macpro Dual-Core Intel Xeon clock 2.66 GHz macos 10.4.9 pci express date 5/11/7 chimera 2382 graphics memory 512 MB main memory 2GB unknown apple graphics driver Molecule (Atoms): Null Wire Stick BStick Ribbon Sphere Ops 1GCN (246): 4439.0 4263.0 827.0 828.0 4344.0 1201.0 11755.0 1YTI (798): 4285.0 4034.0 307.0 307.0 4119.0 475.0 3562.0 2GBP (2575): 3384.0 3217.0 103.0 102.0 3139.0 166.0 1063.0 1GOT (6449): 1833.0 1602.0 41.0 41.0 1702.0 67.0 395.0 2HMG (12189): 461.0 478.0 22.0 21.0 489.0 35.0 143.0 2PDA (18894): 271.0 293.0 14.0 14.0 297.0 22.0 76.0 1YNJ (24369): 211.0 230.0 11.0 11.0 232.0 18.0 56.0 1F4H (33805): 154.0 166.0 8.0 8.0 169.0 13.0 38.0 Matthew Dougherty *** 713-433-3849 *** National Center for Macromolecular Imaging***

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Normal Modes, arrows and more...
by Jean-Didier Marechal 14 May '07

14 May '07

Dear All, I am trying to use chimera to draw arrows of the Normal Modes vectors I previously calculated with charmm. I see different possibilities to provide chimera with the vectors, but how can I draw the arrows? I found a request on the list from Mingfeng Yang that Petter answered in october 2004 regarding a similar problem. Unfortunately the link indicated for VRML does not work anymore. What are the actual features of chimera that would allow me to do something like this ? All the best, JD -- Dr. Jean-Didier Maréchal Professor Assistant Physical-Chemistry Unit Department of Chemistry University Autonomous of Barcelona 08193 Bellaterra, Spain Tel: (+34).93.581.49.36 Fax: (+34).93.581.29.20 e-mail: jeandidier.marechal(a)uab.es

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Re: [Chimera-users] imod model viewing
by Tom Goddard 11 May '07

11 May '07

Hi David, The Chimera IMOD model file reader only handles the meshes in the file. My guess is that the file you made does not contain meshes. Maybe it only has contour lines for the spheres. Or maybe the file format can contain geometric primitives like spheres without contour lines or meshes being specified. I don't know enough about IMOD to be sure. Tom David G. Morgan wrote: > Tom, > > I was trying to use the new IMOD file reader and must be doing something > foolish. I downloaded the newest chimera snapshot release (1.2392) and > the imod.zip file and made a new installation. I can load my IMOD > volume into chimera without any trouble. I then "opened" the IMOD model > file (it opened as an "IMOD segmentation" type). That works without > trouble, but I don't ever see the model. Even trying to use "focus" to > bring it into the field of view gives me a blank field. > > It's possible that my model is the wrong type - I'm playing with chimera > in preparation for needing to do something fancy, so I simply created a > set of spheres of different colors and different radii in IMOD, saved > that model and tried to read it into chimera. I thought I'd simply be > able to read this into chimera and see a couple of spheres, but I don't. > I'm sure I'm doing something silly, but figured I'd bother you while I > play around with it. > > David Gene Morgan > University of California at Davis >

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Question about background transparency
by Vanacore, Roberto M 09 May '07

09 May '07

What are the system requirements to run -bgopacity option in a windows machine? I've tried adding to option (--bgopacity) to the startup command but I can not get a transparent background I'm using Chimera 2.2199 Thanks! Roberto Roberto Vanacore, PhD B-3101 Medical Center North Vanderbilt University Medical Center 1161 Twenty-first Ave South Nashville, TN 37232-2372 Phone: 615-322-7306 Fax: 615-322-7381

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contour levels in Morph Map
by Gabor Papai 09 May '07

09 May '07

Dear all, Is it possible with the Morph Map tool to set the contour levels of the two maps differently? For e.g. if I would like to morph between a map, which is obtained from single particle analysis and has the right contour level of 0.2 - and a second map, which is obtained from tomography and has the right contour level of 2.2, it gives weird result. Other question: does somebody consider to make chimera able to read Imagic files? Thanks for the help! Regards, 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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Chimera-users May 2007