August 2014 - Chimera-users - RBVI Mailing Lists

mmaker question
by Joshua Broyde 21 Aug '14

21 Aug '14

Hi again, I was wondering if the mmaker command had an option (or if there is some other way within chimera) of reporting the RMSD (as calculated by mmaker) of an alignment without actually superimposing one structure on the other. The reason that I am doing this that for a group of structures I can see with mmaker that they superimpose very well, but I want to show that when you compute the RMSD of those same structures when each is bound to a partner they are not quite as well aligned. In essence, what I want mmaker to do is not really realign the structures for me, but to calculated the RMSD of an alignment that I provide it. I looked at the mmaker command page but I couldn't seem to find an option for this. https://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/mmaker.html Thanks again, and Chimera is a wonderful piece of software! Sincerely, Joshua Broyde

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Match two small molecules with command line : "match"
by Jo Sourbron 19 Aug '14

19 Aug '14

Dear, I really appreciate the features that Chimera has (as I read them in yhe user's guide). Though there seem to be a problem: I want to match two small molecules (and in the future maybe more), but If I open the pdb files in Chimera and use the command line match, it says that there is missing an atom spec. Then I looked again in the user's guide and I noticed the "#" that they use. I don't know how what this "#" means. I just want to overlap the two structures and get a percentage of homology or something like that. That would be great. You can always contact me, kind regards, Jo Sourbron PhD Student Laboratory for Molecular Biodiscovery Department of Pharmaceutical and Pharmacological Sciences Katholieke Universiteit Leuven O&N2, Campus Gasthuisberg Herestraat 49, box 824 B-3000 Leuven, Belgium j.sourbron(a)gmail.com GSM. +32 474 94 84 17 TEL. +32 16 37 78 07 http://be.linkedin.com/pub/jo-sourbron/33/496/77a/

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Ligand Problem
by Marcus Fabiano A. Mendes 15 Aug '14

15 Aug '14

Hi, My Name is Marcus, and I am a huge fan of Chimera. Currently, I'm using Chimera to visualize p:MHC complex and it's electrostatic potential map. p:MHC occurs as an α chain composed of three domains - α1, α2, α3, β2 microglobulin and a ligand present in the groove. Chimera automatically recognizes the epitope as a ligand, since they have on average less than 10 amino acids. There's someway to make the Chimera don't recognizes this epitope as a ligand? A option to set the parameters that Chimera uses (ligand = <10 amino acids)? Thanks for All SincerelyMarcus Mendes

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Re: [Chimera-users] Volume viewer chimera
by Elaine Meng 15 Aug '14

15 Aug '14

On Aug 15, 2014, at 2:08 AM, Matteo Allegretti <maallegr(a)biophys.mpg.de> wrote: > Dear prof. Meng, > it would be possible in the future to have more than three panels on the > volume viewer of Chimera? > Thank you so much, > Matteo > -- > Matteo Allegretti > PhD candidate > Max Planck Institut für Biophysik > Max-von-Laue-Straße 3 > D-60438 Frankfurt am Main > Office: +49-69-6303-3015 Dear Matteo, If you mean showing the histograms of more than 3 datasets at the same time, you can already do that. In Volume Viewer menu, choose "Features… Data display options", and then in the resulting options you can increase the “Maximum number of histograms shown” from 3 to some bigger number. It’s better if you send Chimera questions and suggestions/discussion to the chimera-users(a)cgl.ucsf.edu address (CC’d here) instead of directly to me. There are other people who also answer the questions, and I might be gone or not know the answer. Thanks! 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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does chimara allow changing of the primary sequence of the protein?
by Marta Mikolajczak (BIO) 14 Aug '14

14 Aug '14

Dear Sir/Madam, I am a PhD student working for the University of East Anglia. I have just downloaded the Chimera software and I really like the look of it. So far I have found it very user friendly. I was wondering if the software allows incorporating changes into the protein structure? I am working on the mutant of my protein of interest. I have found, through experimental procedures, that when I mutate one residue it changes the properties of the protein. I was wondering if the effects I am seeing are due to changes in the protein structure. I would like to visualise it. I am not interested in generating crystal structure of the mutated protein or anything like that. I really would like to insert a different amino acid into the structure that already exist. I understand it might be incorrect but all I want to achieve is a "prediction". Would chimera software do that for me? Kind regards, Marta Mikolajczak

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Error with partial charge calculation during minimisation
by Ahir Pushpanath 13 Aug '14

13 Aug '14

Hey there, whenever I try to do a minimisation of a ligand in presence of protein, with a few residues selected as flexible , rest held as rigid, I get past the adding hydrogen box, but it always has a error saying it cant calculate partial charge for the first N-terminal residue, N atom , for example. If I try and delete that residue, it just moves up and says it cant do it for the second one. The PDB file seems fine, and I have opened in Discovery studio and seen it has partial charges assigned fine. Can you enlighten me on what maybe going wrong? I am using the latest build of Chimera. PDB is 1BW9 chain A (only one conformation chosen in multiple conformation residue positions). The ligand is the PPY inside. the flexible residues are all those 5A away apart from NAD. -- Dr. Ahir Pushpanath* PhD.* Senior Biologist, Johnson Matthey.

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Surface color by electrostatic potential
by roz orchidea 13 Aug '14

13 Aug '14

Dear all, I am trying to get some images of the electrostatic potential surface of my complex. But I have noticed that by using the same .dx file in chimera and vmd, I am getting different coloring results. Chimera gives more negatively charged areas. I used the -5 0 5 coloring for both. Is it a difference in reading the .dx files between the 2 software? I also think that Chimera colors each side chain by the avg charge. Is it possible to have a more detailed coloring of the surface according the charges? Thanks in advance, Alexandra

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Re: [Chimera-users] [chimera-dev] Feature request
by Elaine Meng 11 Aug '14

11 Aug '14

Dear Xavier, I personally don’t recommend the Chimera/Povray approach… my neon/conic suggestion is better-looking, but not as easy as the feature you request. There is limited programmer time, so I can’t say it will happen, but we can put it on the list of requests. You can enable showing backbone atoms at the same time as ribbon with command “ribbackbone” — then try displaying the carbonyls. You may also need to unchain (avoid drawing long bonds between different carbonyls, e.g. command: setattr m autochain 0). However, the default ribbon path is smoothed, so in some places the backbone atoms will appear to be floating away from the ribbon. You can try reducing that problem by using a different method to calculate the ribbon path, for example, with command: ribspline cardinal smooth strand …but see the manual for other command options and parameters. The cardinal spline tries to follow CA positions, so it is still possible you won’t be able to totally eliminate spaces between ribbon and C atoms. It may be necessary to show the C atoms as balls (slightly larger than stick-ends) to obscure the gapping. The ribbackbone and ribbon path issues are discussed in more detail here: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/ribbonstyle/ribbo…> I hope this helps, Elaine On Aug 11, 2014, at 1:48 AM, F.Xavier Gomis-Rüth <xgrcri(a)ibmb.csic.es> wrote: > Dear Elaine & Eric, > thanks again for your and Eric's suggestions. The issue is that the POV-Ray rendering is not as attractive as the CHIMERA rendering. > Would it be possible to kindly and humbly request that this minor feature be implemented at a certain time point in a new version > of the program :-) ? > Another issue I have currently problems with: > it would be very helpful to be able to display the main-chain carbonyls sticking out from the ribbon at the right place. I tried with the > licorize option of the ribbon trace but it was not solving the problem. This is particularly helpful when representing e.g. metal-binding sites. > Thanks again for your help and dedication to constantly improve this fantastic program. > Best wishes, > Xavier > > On 1/8/14 9:11 PM, Elaine Meng wrote: >> A few caveats of the Povray approach: >> In my tests (current daily build), it always makes cylinders with the same aspect ratio regardless of whether I am showing the lines as dotted or dashed in Chimera. Also, it is hard to tell they are cylinders unless you make the linewidth fairly large. >> >> Elaine >> >> On Aug 1, 2014, at 11:28 AM, Eric Pettersen >> <pett(a)cgl.ucsf.edu> >> wrote: >> >> >>> Hi Xavier, >>> In addition to Elaine's neon suggestion, if when you save an image you change the rendering from "Chimera" to "POV-Ray" then any dashed or dotted lines will be converted into equivalent cylinders and spheres in the POV-Ray image. I've attached an image that shows how a distance looks. >>> >>> --Eric >>> >>> > > -- > <fxgr_signanew.jpg>

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huge electrostatic range for APBS
by Dennis N Bromley 07 Aug '14

07 Aug '14

Hi all, I have two proteins models from different points in an MD simulation. I colored the surface by Coulombic Surface Coloring, which ran AnteChamber and such. Then I ran APBS. When I color by the APBS data, they look more or less similar. But when I click the "Set full range" button, the kBTe unit range on one is about +-3 and the unit range on the other is about +-300. Any ideas why one would be so much larger? Or am I misinterpreting something? Both were run with exactly the same parameters, all default except for temperature = 310. thanks- -denny-

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"match" command with serialNumber specifier
by Hiroyuki ISOBE 06 Aug '14

06 Aug '14

Dear Sir: I would like to run “match” with two models by using serialNumber specifiers but fail to specify multiple atoms. I would like to match the following sets of atoms: SerialNumber=14,31,91,74 for model #0 and SerialNumber=74,91,31,14 for model #1 How should I include multiple atoms in the command line? The command for one atom, match #1/serialNumber=14 #0/serialNumber=74 works nicely, but I cannot include, for instance, two atoms with match #1/serialNumber=14,31 #0/serialNumber=74,91 or match #1/serialNumber=14 31 #0/serialNumber=74 91 Could you please let me know the correct commands for this purpose? Thank you for your kind help in advance. Sincerely, Hiroyuki -- Hiroyuki ISOBE Advanced Institute for Materials Research (WPI-AIMR) Department of Chemistry Tohoku University Sendai, 980-8578, Japan Tel: +81-(0)22-795-6585 Fax: +81-(0)22-795-6589 Email: isobe(a)m.tohoku.ac.jp Homepage: http://www.orgchem2.chem.tohoku.ac.jp

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Chimera-users August 2014