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Re: [Chimera-users] findhbond/5750 (FindHBond failure)
by Eric Pettersen 22 May '08

22 May '08

Hi Tyler, The problem is that Chimera "knows" the atom types of standard residues and doesn't try to compute them from scratch. Therefore it assigns ND1 in HIS a sp2 type, which throws a monkey wrench into the find-hbond computation as it looks for the planarity of the ND1 and sees it bonded to nothing! For what you want to do, you want to get that atom's residue changed. Do this: 1) Control-double click on the ND1 atom 2) Chose "Modify Atom" from the resulting popup menu. 3) Change the "Element" to "N"; leave "Geometry" as "tetrahedral" 4) Change "Bonds" to 3 5) In the "Residue Name" section, use the "new residue" option with "NH3" as the name and chain "het" 5) Click the Change button That should give you what you want. --Eric Eric Pettersen UCSF Computer Graphics Lab http://www.cgl.ucsf.edu On May 22, 2008, at 10:25 AM, Tyler Arbour wrote: > Wow, I didn't expect a response for this...great! I was actually > just trying to create a figure representing a computational model > that I am using. Starting from the crystal structure, I wanted to > actually change the histidinal N to a simple NH3 molecule. I am > just trying to get familiar with Chimera--I usually use DS > Viewerpro for modifying structures, and it doesn't seem like > Chimera is well-suited to this type of modification. If you have > any advice on an easy way to make this conversion so that I have a > nice figure, I'd greatly appreciate it! Thanks. > > Tyler > > On May 22, 2008, at 11:17 AM, Eric Pettersen wrote: > >> Hi Tyler, >> Your structure seems to have a histidine residue (residue 159 in >> chain A) that consists solely of an ND1 atom! How did you manage >> that? >> >> --Eric >> >> >> Eric Pettersen >> UCSF Computer Graphics Lab >> http://www.cgl.ucsf.edu >> >> >

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Re: [Chimera-users] building linker peptide
by Elaine Meng 22 May '08

22 May '08

On May 21, 2008, at 1:29 AM, Fabian Glaser wrote: > Another question regarding this issue, I succeded to make a new > bond and minimize it between two chains, A and B, in the same pdb. > But this created apparently a problem with the residue numbering > and Nterm recognition, since when I tried to add an additional > linker to the chimera I created, I got the following error message: > > "No MMTK name for atom "H" in standard residue ALA" > > I suspect that this is related to the fact that I still have two > chains, and Chimera does not identified the new bond, or something > similar. > > Is there a way to automatically rename the newly unified chains? > Any suggetion will be highly appreciated. Hi Fabian, There is no automatic way to change chain ID. Only the ugly manual text-editing way, sorry! I guess that the ATOM part of the file no longer agreed with the SEQRES part of the file. It might work to simply delete that atom, if it looks like it is extra. However, I would probably go back to a PDB file saved after you added all your linker residues and edit it to remove all the lines except the coordinates (the ATOM and HETATM lines), remove the chain IDs, and renumber all the residues. It is necessary to renumber the residues because there may be residues with the same number in the different chains, and now there would be no way to tell them apart (for example, two different residues numbered 10, which used to be residue 10 in A and residue 10 in B). Unfortunately you will lose the ability to use the "familiar" residue numbering within the second chain. I attached a fortran (f77) program to do this editing, but I realize you may not be able to use it depending on your computing environment. If you are on some unix-type computer you would just compile it with something like: f77 renum2.f -o renum Then execute it with renum It would ask for the names of the input and output PDB files and what residue number to start with. Then you would have to do the addh/addcharge/minimization stuff again, sorry. I think it would already have the bond you wanted, however. Maybe someone else can think of a more elegant approach. Best, 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

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Stereo projection
by Magali Cottevieille 21 May '08

21 May '08

Hi, Is there any way, with two projectors piloted by two graphic cards, to send from Chimera the stereo left eye view onto one, and the stereo right eye view onto the other one ? These two projectors are meant to be used with filters and special glasses to create a 3D view. Thanks for your help! -- Magali Cottevieille, Ph.D. Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biophysics, 630 W 168th St, P&S Black Building 2-221 New York, NY 10032 Ph: (+1) 212-305-9521 Fax: (+1) 212-305-9500 Email: mc3077(a)columbia.edu magali.cottevieille(a)gmail.com

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Stereo projection
by Steven Ludtke 21 May '08

21 May '08

Yes, we have done this before, though I don't remember with absolute certainty if we did it with chimera. You don't use 2 video cards normally, but rather 1 card with 2 outputs. Also, you will need one of the 'professional' cards where the driver supports stereo in a window ie- NVidia Quadro (we didn't try ATI). The NVidea stereo drivers then have a mode for this type of stereo, or at least that's my memory, it was a year or two ago when we demonstrated this. You need: 2 identical projectors which permit geometry correction so their corners can be exactly aligned 2 polarizer plates. we got (http://www.3dstereo.com/viewmaster/pj-pfilt-3x3.html ) for $20 a pair linear polarizing glasses (from the same site) Quadro or similar GFX card Note that with this type of stereo, you could technically make this work with any old dual output 3-D card, but you would have to write the visualization software so it would open 2 display windows with slightly different orientations that you could then manually (or automatically) position on each of the 2 projectors. We did this just as an initial proof of concept, and haven't managed to get back to it again, though we keep meaning to, as it is MUCH cheaper than the commercial solutions. Oh, one warning, the polarizer plates mentioned above are plastic, and the light energy put out by your typical projector is quite substantial. We actually melted one of the polarizers on our first attempt, despite using much of it's 3x3 inch surface area. ie - use a low power projector, or put the polarizer between thick glass plates or somesuch... > From: Magali Cottevieille <mc3077(a)columbia.edu> > Date: May 21, 2008 3:06:07 PM CDT > To: chimera-users(a)cgl.ucsf.edu > Subject: [Chimera-users] Stereo projection > > Hi, > > Is there any way, with two projectors piloted by two graphic cards, to > send from Chimera the stereo left eye view onto one, and the stereo > right eye view onto the other one ? These two projectors are meant > to be > used with filters and special glasses to create a 3D view. > Thanks for your help! > > -- > Magali Cottevieille, Ph.D. > Howard Hughes Medical Institute, > Department of Biochemistry and Molecular Biophysics, > 630 W 168th St, P&S Black Building 2-221 > New York, NY 10032 > > Ph: (+1) 212-305-9521 > Fax: (+1) 212-305-9500 > > Email: mc3077(a)columbia.edu > magali.cottevieille(a)gmail.com > > _______________________________________________ > Chimera-users mailing list > Chimera-users(a)cgl.ucsf.edu > http://www.cgl.ucsf.edu/mailman/listinfo/chimera-users > ---------------------------------------------------------------------------- Steven Ludtke, PhD | Baylor College of Medicine sludtke(a)bcm.tmc.edu | Associate Professor & Co-Director stevel(a)alumni.caltech.edu | National Center For Macromolecular Imaging V: (713)798-9020 | Dept of Biochemistry and Mol. Biol. F: (713)798-1625 | | Those who Do, Are http://ncmi.bcm.edu/~stevel | The converse also applies

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Re: [Chimera-users] Low resolution surface model
by Elaine Meng 21 May '08

21 May '08

On May 20, 2008, at 10:21 PM, Damien Larivière wrote: > Dear Elaine, > Here is what I would like to do with Chimera : > > From Tools/Structure analysis/sequence, it is possible to copy a > portion of the aminoacid sequence of a protein and then to > highlight in an other color this portion of sequence in a high > resolution surface model (Actions / surface / show). > > I would like to highlight a given portion of sequence but in a low > resolution surface model. I tried High-Order Structure / Multiscale > models with no success. > > Thanks for you help and congratulations for the work you perform. > Damien > ------------------------------------------ > Damien Larivière > Fourmentin-Guilbert Scientific Foundation > 2 Av. du Pavé Neuf, 93160 Noisy-le-Grand, France > Phone : + 33 1 43 03 06 20 > Cell phone : +33 6 82 19 81 32 > damien.lariviere(a)fourmentinguilbert.org > Hi Damien, You can color a low-resolution surface for certain residues, but it takes an additional step as compared to coloring the high-resolution surface. Another difference is that it is done by distance cutoff, because it is no longer clear exactly which atom goes with which point on the surface. (1) First create the low-resolution surface. I can think of two different ways: (a) Multiscale Models - click "Make Models" and that will create a separate low-res surface for each chain. In that dialog, if you select "All" chains you can then edit the resolution value for those surfaces. http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/multiscale/ framemulti.html (b) command "molmap" - it makes a density map from the atomic coordinates, which you can then display as an isosurface. The Volume Viewer tool is automatically opened to show the density; in that tool, you can drag a bar on the histogram to change the contour level. In this case, all the atoms in the structure are used, and so you would get one "blob" (depending on contour level, though) rather than separate surfaces per chain. Volume Viewer has many additional options including surface smoothing (see Features... Surface and Mesh options). http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/molmap.html http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/volumeviewer/ framevolumeviewer.html (2) Select the residues and perform the coloring. This can be done exactly the same as for the high-resolution surface, and there are many different ways. To select the residues, you can use the Sequence tool (as you described), or the Select menu, or commands; to perform the coloring, you can use Actions...Color or the "color" command. However, the low-res surface will not be colored yet... (3) Use Color Zone (under Tools.... Volume Data) to color the surface to match the atoms you just colored. This just uses a simple distance cutoff and colors parts of the surface to match the closest atoms. After clicking Color, you can just drag the slider to change the distance cutoff. You're welcome! I hope this helps, Elaine P.S. we are working on better integration of different kinds of surfaces, so this procedure may change in the future ----- 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

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reporting sigma values for electron density maps
by David Chenoweth 20 May '08

20 May '08

Hi! Can you please let me know if there is a way to report or set the sigma value for an electron density map from a high resolution crystal structure. I am using a ccp4 FWT.map and DELFWT.map file for structures <1.2 angstrom resolution. Can I somehow find the sigma value that corresponds to the Level setting in the Volume viewer? Thanks, Dave Chenoweth ********************************************** David M. Chenoweth California Institute of Technology Division of Chemistry and Chemical Engineering Mail Code: 164-30 1200 California Boulevard, 91125 Pasadena California, USA Phone: 626-395-6074 Email: dchen(a)caltech.edu **********************************************

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saving multiple maps
by odonnell＠chem.fsu.edu 19 May '08

19 May '08

Similar to saving multiple PDB's as a single PDB file, is there a way to save multiple maps (e.g mrc or ccp4) as a single map file. Thanks in advance for anything which could help me out!! -Jason ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.

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building linker peptide
by Fabian Gmail 18 May '08

18 May '08

Dear Chimera experts, I am willing to build a peptide "linker" connecting two different pdb chains, that is to connect two existing pdb chains with a new peptide chain, and if possible minimize it. Is it possible to do that wich chimera? I know the command addaa, but to my best understanding this command it's not able to connect the end of the new peptide with the beginning of the second chain. Any suggestions will be greatly appreciated. Best regards and thanks a lot in advance, Fabian -- Fabian Glaser, PhD Bioinformatics Knowledge Unit, The Lorry I. Lokey Interdisciplinary Center for Life Sciences and Engineering Technion - Israel Institute of Technology Haifa 32000, ISRAEL Web: http://bku.technion.ac.il Email: fglaser(a)tx.technion.ac.il Tel: +972-(0)4-8293701 Cel: +972-(0)54-4772396

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Action focus
by Thomas Goddard 15 May '08

15 May '08

I made Action / Focus work on selected surfaces. Also I made the none-implies-all rule include surfaces in the "all". So Actions / Color / green will color everything green including surfaces if nothing is selected. I fear this a bit because volume user often have tens of maps and pdb models open and could shoot themselves in the foot pretty easily. These changes were a bit more complicated than expected and may be a buggy. Report anything suspicious or wait until next week when I shake it down a bit more. Tom

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electrostatic potential colored surfaces script
by Miguel Ortiz-Lombardía 15 May '08

15 May '08

Dear all, I wonder if someone has written and would share a script to sequentially read a pdb file, show its molecular surface and color it by the electrostatic potential from an appropriate .dx file. Cheers, Miguel -- http://www.pangea.org/mol/spip.php?rubrique2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Je suis de la mauvaise herbe, Braves gens, braves gens, Je pousse en liberté Dans les jardins mal fréquentés! Georges Brassens

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