September 2015 - Chimera-users - RBVI Mailing Lists

FW: How can I find H-bond between ligand and protein residues within selected angstrom?
by Williams, Joanne 25 Sep '15

25 Sep '15

On 9/19/15 1:29 AM, "高木友理子" <kagaribi-firefly(a)bs.s.u-tokyo.ac.jp> wrote: > Dear Chimera creator, > > I use Chimera to analyse protein-ligand interaction. > Especially, I would like to find H-bond between these. > I clicked HBonds and tried to search H-bond within selected distance. > However,I could not. > I guess the reason is that I was not able to understand "Relax > constraints" in H-Bond parameter window. > I ,of course, checked chimera's help. > What is relax constraints? > What does 0.4 angstroms indicate? Is this the Max distance between ligand > and protein residue? > I would like to find H-bond between them within selected angstrom. > What should I do to know that? > Please teach me how to do. > Thank you for being patient with my English. > > Best regards, > > Yuriko Takagi > Tokyo university student

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Way to extract path to file from model ID
by Oliver Clarke 24 Sep '15

24 Sep '15

Hi all, I’m wondering, is there any way (presumably via a python function) to get the path to the original file from the model ID? I’ve written a little python jiffy (below) so I can lowpass filter maps to a specified resolution on the fly inside chimera using EMAN, but is quite slow because I need to first write a copy of the map out (so I know where it is) and then modify it. If anyone knows of an easier way to do such things I would be most grateful. Cheers, Oli. Script: def cmd_lowpass(lowpass,args): from Midas.midas_text import doExtensionFunc def lowpass(model,resol): import os from chimera import runCommand import subprocess import sys #You may need to change the below to .bash_profile if on mac. #You must have EMAN2 in your bash path for this to work correctly. #If running multiple times, you need to close the first instance of lowpass.mrc before creating a second. bashrc_path=os.path.expanduser("~/.bashrc") freq=1.0/resol command="cd ~; system mkdir chimera_tmp; cd chimera_tmp; volume "+model+" save ./tmp1.mrc" runCommand(command) pathvar=os.path.expanduser("~/chimera_tmp") os.chdir(pathvar) e2string="--process=filter.lowpass.gauss:cutoff_freq="+str(freq) print(e2string) mrc_in=pathvar+"/tmp1.mrc" mrc_out=pathvar+"/lowpass.mrc" e2command="source "+bashrc_path+"; bash -c \"e2proc3d.py"+" "+mrc_in+" "+mrc_out+" "+e2string+"\"" print(e2command) proc=subprocess.Popen(e2command,stdout=subprocess.PIPE, stderr=subprocess.PIPE,shell=True) out, err = proc.communicate() print 'stdout:', out print 'stderr:', err runCommand("open lowpass.mrc") doExtensionFunc(lowpass,args) from Midas.midas_text import addCommand addCommand("lowpass", cmd_lowpass, help=False)

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Rendering protein molecule to a geometry format by Chimera
by Hsin-Yi Yeh 23 Sep '15

23 Sep '15

Hi, I try to render a protein molecule to a geometry format (from .pdb format to .obj format) by Chimera. I use 'Multiscale models' tool in 'Higher-Order Structure' choice and then make the model by resurfacing at some appropriate resolution. It turns out that the whole protein molecule can be modeled pretty nicely. However, I now have a similar problem; instead of rendering the whole protein molecule, I would like to render the whole structure separately. I want to render the exposed residues (those residues on the surface) and non-exposed/buried residues separately, so I will have two obj files (one for the exposed residues and the others for the non-exposed residues). I haven't been able to figure this problem out yet. Thus, I am wondering could you please give me some direction? Any advice will be greatly appreciated! Thank you, Hsin-Yi (Cindy) Yeh -- Hsin-Yi (Cindy) Yeh PhD Student Parasol Lab, Department of Computer Science and Engineering Texas A&M University Email: hyeh(a)cse.tamu.edu https://parasol.tamu.edu/people/hyeh/

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applying charges calculated by DFT to ligands in protein models
by Anne-Frances Miller 21 Sep '15

21 Sep '15

Dear Sir or Madam, Our protein has a bound FMN and the various tools accessible via Chimera are not able to apply charges to the atoms in FMN. However I have NBO charges for all the atoms from DFT calculations. Is there a way I can provide these to the FMN in my pdb file or in my Chimera session in order to then display a Coulomb electrostatic potential for the protein + FMN? My charges are not simply +1 or -1, but fractional charges for each atom. Can Chimera accommodate this ? If not, no problem, I will still benefit greatly even if all I can do is add -1 to the one atom at which most of the excess electron density is concentrated. Many Thanks, Anne-Frances Anne-Frances Miller Professor of Chemistry Director, Magnetic Resonance Centre University of Kentucky Dept. Chemistry, 505 Rose Street Lexington KY 40506-0055 “You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete.” Buckminster Fuller

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Fetch by ID EMDB + fit PDBs enhancement suggestion
by Ingvar Lagerstedt 21 Sep '15

21 Sep '15

Dear Chimera, Attempting to Fetch by ID an EMDB entry with a fitted model, where the model does exist in PDB format, causes an error: No such ID. The map is retrieved but not opened in Chimera. The two main reasons that the model is not available: A. The model is only available in mmCIF format. Since a wwPDB remediation at the end of last year, entries that are larger than what the PDB format can handle are no longer distributed as split entries. They are only distributed as mmCIF (and PDBx) files. This is common for say ribosomes. EMD-6315 with fitted model 3j9z is an example. Changing the command so that it attempts to retrieve mmCIF files rather than PDB files would fix this issue. B. The model has not been released, EMDB and PDB releases for maps and models are not always synchronised. An example would be EMD-6413, where the model 3jb9 is currently waiting for author approval. In this case it would be nice if the map was loaded. Many Thanks, Ingvar

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Re: [Chimera-users] large file size exporting scene with spheres
by Elaine Meng 17 Sep '15

17 Sep '15

On Sep 17, 2015, at 10:48 AM, Tom Goddard <goddard(a)sonic.net> wrote: Hi Elaine, Bill, Chimera export first writes x3d and then converts that to STL or VRML or whatever you requested. For atom spheres it writes the center and radius of the sphere in x3d. It does not write the number of triangles or the amount subdivision. The Chimera program x3d2stl controls how many triangles a sphere is turned into. It uses 100 triangles per square Angstrom. There is no option to change that. But it is possible to run x3d2stl by hand and specify the resolution option “-r 1” to request 1 triangle per square Angstrom, resulting in a file that is 100 times smaller and the spheres still look fine (using about 40 triangles per atom). ~/Desktop/Chimera\ 1.10.2.app/Contents/Resources/bin/.x3d2stl -o 1a0m_r1.stl -r 1 < 1a0m.x3d Note that .x3d2stl has a period as the first character. Eric Bell reported this problem about a year and a half ago but the ridiculous defaul STL sphere subdivision has unfortunately not been changed. http://plato.cgl.ucsf.edu/trac/chimera/ticket/13183 Tom > On Sep 17, 2015, at 9:51 AM, Eliason, William <william.eliason(a)yale.edu> wrote: > > Elaine, > > Thanks again for your suggestions. I had already seen that previous post you listed and found that the stl file size for spheres was unchanged with changes to the zoom. The subdivision box in the effects tool changes the spheres on on the chimera display but has no effect on the stl file size when exporting a scene. > > I will keep looking for a solution. If you have any other suggestions please email me. > > Thanks Again, > > Bill > ________________________________________ > From: Elaine Meng [meng(a)cgl.ucsf.edu] > Sent: Tuesday, September 15, 2015 3:42 PM > To: Eliason, William > Cc: chimera-users(a)cgl.ucsf.edu > Subject: Re: [Chimera-users] large file size exporting scene with spheres > > Hi Bill, > You can decrease the “subdivision” setting in the Effects dialog (menu Tools… Viewing Controls… Effects) and also zoom out the view before exporting. > > These are discussed in more detail in this previous post: > <https://urldefense.proofpoint.com/v2/url?u=http-3A__plato.cgl.ucsf.edu_pipe… > > > 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 > > > >> On Sep 15, 2015, at 11:52 AM, Eliason, William <william.eliason(a)yale.edu> wrote: >> >> Chimera-users, >> >> I am very new to chimera. I would like to export a scene with spheres for 3d printing but the ( .stl) file size is enormous. They contain way to many triangles. I tested a smallish molecule in MeshLab and I could decrease the number of faces from 699732 (34MB) to 34986 faces (1.7MB) with minor flattening of the sphere. Is there a way to have chimera generate spheres with fewer faces? >> >> Thank you, >> >> Bill Eliason > >

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Saving sessions including maps?
by Oliver Clarke 17 Sep '15

17 Sep '15

Hi all, Is there any possibility of altering the chimera session format (or adding a separate option) such that all maps (including those created during the session) are also saved? This would greatly facilitate sharing data with collaborators, and would also allow one to provide chimera sessions with saved scenes as supplementary data when publishing. It would also make saving sessions more practical when many different volumes are created during the session - for example, when using a molmap low resolution representation for each domain. This would not necessarily require creating a new format - just creating a tarball or folder with all the maps and relative paths specified in the python file would work fine I think? Cheers, Oli.

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Re: [Chimera-users] FW: eps image in publication quality
by Mahendra B Thapa 16 Sep '15

16 Sep '15

Dear Eric & Greg Thank you for the suggestions. The only available option to save the *sequence alignment image* is EPS format, actually I am looking a way to save the image in tif or png format. In the pop-up window of sequence alignment image , there are following options available under 'File' heading: Save as, save EPS, save Association info, Hide & quit. As Greg pointed out, I didn't find "Save Image dialog". Eric, when I copied the so generated EPS image in MS-Powerpoint for further editing, the quality of the image was not good. I have attached one of the EPS image ( in which I have aligned two structures: pdb id 4ICB & 3BCI.) Thank you for help, Mahendra Thapa University of Cincinnati,OH On Tue, Sep 15, 2015 at 8:42 PM, Thapa, Mahendra (thapamb) < thapamb(a)mail.uc.edu> wrote: > > ------------------------------ > *From:* gregc(a)cgl.ucsf.edu > *Sent:* Tuesday, September 15, 2015 6:42:06 PM (UTC-06:00) Central America > *To:* Eric Pettersen; Thapa, Mahendra (thapamb) > *Cc:* chimera-users(a)cgl.ucsf.edu > *Subject:* Re: [Chimera-users] eps image in publication quality > > Actually, chimera's EPS files are at a fixed resolution. To get a higher > resolution, save the image with a higher resolution. An easy way to get a > reasonable resolution is to switch to print units in the Save Image dialog, > and choose a size in inches or cm. The default "Print resolution" of > 100dpi is generally more than adequate since printers need many dots to > represent a single pixel and most computer monitors are roughly 100dpi. > > Also, note that EPS files are huge compared to PNG or TIFF files. Most, > if not all, journals now accept TIFF or PNG images, so there is no need to > generate an EPS file. > > -- Greg > > September 15 2015 5:18 PM, "Eric Pettersen" <pett(a)cgl.ucsf.edu > <%22Eric%20Pettersen%22%20%3Cpett(a)cgl.ucsf.edu%3E>> wrote: > > EPS (Encapsulated PostScript) is resolution independent — it essentially > has infinite resolution. If it doesn’t look good in a viewer it’s because > the viewer is doing a poor job of rendering it. What are you using to look > at the EPS file? > —Eric > > Eric Pettersen > UCSF Computer Graphics Lab > > > > On Sep 15, 2015, at 9:04 AM, Mahendra B Thapa <thapamb(a)mail.uc.edu> wrote: > > Dear Chimera Users, > Using the following procedures in chimera window, I saved a sequence > allignment image in eps format ( which looked like the first image of " > file:///opt/UCSF/Chimera64-1.6.1/share/chimera/helpdir/ContributedSoftware/multalignviewer/framemav.html"). > The image in the pop of window is nice but the saved image in the eps > format is not so clear. Let me suggest how to save the image in the > publication quality. > (i) structure ---> matchmaker > (ii) Tools ---> sequence ---> match ---> align > (iii) file ---> save as ---> eps > Thank you, > Mahendra Thapa > University of Cincinnati, OH > _______________________________________________ > Chimera-users mailing list > Chimera-users(a)cgl.ucsf.edu > http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users > >

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large file size exporting scene with spheres
by Eliason, William 16 Sep '15

16 Sep '15

Chimera-users, I am very new to chimera. I would like to export a scene with spheres for 3d printing but the ( .stl) file size is enormous. They contain way to many triangles. I tested a smallish molecule in MeshLab and I could decrease the number of faces from 699732 (34MB) to 34986 faces (1.7MB) with minor flattening of the sphere. Is there a way to have chimera generate spheres with fewer faces? Thank you, Bill Eliason

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eps image in publication quality
by Mahendra B Thapa 15 Sep '15

15 Sep '15

Dear Chimera Users, Using the following procedures in chimera window, I saved a sequence allignment image in eps format ( which looked like the first image of "file:///opt/UCSF/Chimera64-1.6.1/share/chimera/helpdir/ContributedSoftware/multalignviewer/framemav.html"). The image in the pop of window is nice but the saved image in the eps format is not so clear. Let me suggest how to save the image in the publication quality. (i) structure ---> matchmaker (ii) Tools ---> sequence ---> match ---> align (iii) file ---> save as ---> eps Thank you, Mahendra Thapa University of Cincinnati, OH

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Chimera-users September 2015