August 2015 - Chimera-users - RBVI Mailing Lists

color suggestion
by Dougherty, Matthew T 26 Aug '15

26 Aug '15

1) button on the model panel to bring up the color editor that will edit the model selected. 2) very short pulldown menu on the color editor of the primary & secondary colors, along with black, white and gray50. Matthew Dougherty National Center for Macromolecular Imaging Baylor College of Medicine ===========================================================================

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Re: [Chimera-users] a question relate to Chimera
by Elaine Meng 26 Aug '15

26 Aug '15

On Aug 25, 2015, at 6:16 PM, Smith Liu <smith_liu123(a)163.com> wrote: > Dear Elaine, > Here there is a sentence "a particle has a diameter of 100 pixels and the width of the reconstruction box is 256 pixels". Will you please tell me by Chimera how can I know the diameter of the particle and the width of the reconstruction box, as described in the cited sentence? > > I am looking forward to getting a reply from you. > Best regards. > Smith Dear Smith, It is recommended to send Chimera questions to chimera-users(a)cgl.ucsf.edu (CC’d here) instead of to me directly. I don’t know where that sentence came from, so I’m not even sure it is a Chimera question. By “pixels” maybe the authors mean grid units. They probably just knew this about their own data without trying to get it from Chimera, but at least for the width of the box, you can see the grid dimensions just to the right of the dataset name in the Volume Viewer dialog. <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/volumeviewer/fram…> Best, 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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on point-group symmetry used for the 3-D calculation
by Smith Liu 25 Aug '15

25 Aug '15

Dear All, By chimera, can we know the point-group symmetry used for the 3-D calculation? Best regards. Smith

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on voxel size measured in angstroms
by Smith Liu 25 Aug '15

25 Aug '15

Dear All, Will you please tell me by Chimera how can we know the voxel size measured in angstroms? Smith

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is the connection present?
by Dmitry 25 Aug '15

25 Aug '15

Dear Colleagues, I have 3d tetramer volume density where I fitted known x-ray structure of monomer (to each unit of tetramer). I want to check the inter-monomeric space, whether there is connections between 2 monomers. Is there a command or script that checks the presence of contacts between bounds of 2 structures? Thank you Sincerely, Dmitry

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Electrostatic Potential Visualization
by Chun, Minju 25 Aug '15

25 Aug '15

Hello, I am an intern working with Chimera, and I was wondering if I was missing a plug-in that calculated electrostatic potential. I attempted to load a dx and cube file to emulate electrostatic potential, but there seemed to be a problem finding/reading the files(perhaps I'm doing this wrong too). I thought that if I calculated electrostatic potential directly with Chimera, I could see electrostatic potential. It says on your website that Chimera can calculate the electrostatic potential with APBS: "electrostatic potential calculated with Adaptive Poisson-Boltzmann Solver<http://www.poissonboltzmann.org/apbs/> (APBS); the APBS<http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/apbs/apbs.html> tool in Chimera runs this program via web service provided by the NBCR<http://nbcr.ucsd.edu/>" Do you have a tutorial that goes in more detail in how to calculate potential with APBS? Thank you, Minju Chun

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Flattening of coloured icosahedron
by R.I.Koning＠lumc.nl 24 Aug '15

24 Aug '15

Is it possible to flatten a coloured icosahedron surface? I have an electron density of a virus, and using shape icosahedron and colour icosahedron surface and surface colour I can colour it according to this density. I would really like to generate a flattened icosahedron (compared to the flatten icosahedron command) from the coloured icosahedron surface. In order to get a 2D map of the colours. Is this possible somehow in Chimera? Is it otherwise possible to export the icosahedron with the coloured surfaces and try in another program (like Maya of Cinema4D?). Best regards, Roman Koning

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layering problem
by Joseph Atherton 20 Aug '15

20 Aug '15

Hi! I'm trying to make videos at the moment but I have a problem with layering, as in the model seems to be 'hiding' behind the density even when the density is transparent. This occurs when I set transparency also in the model, even at low transparency (e.g command #19:transparency 5,a,r #0:259-271). See the example attached- the left hand most part of the model, and the ADP is hidden when their transparency is non-zero. Can I prevent this? Cheers, Joe

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Re: [Chimera-users] [chimera-dev] distance measurements
by Elaine Meng 20 Aug '15

20 Aug '15

Hi Feixia! Yes, you could use Chimera to measure all lysine CA-CA distances in many structures, but it would require some scripting to loop through the structures, find the lysines, and do the measurements. There is some information on looping through structures and running Chimera commands here: <http://www.rbvi.ucsf.edu/chimera/docs/ProgrammersGuide/basicPrimer.html> Now, for each structure, you might imagine the script should first find all the lysines and then use the “distance" command on each pairwise combination, substituting in the proper residue numbers. However, there is an easier way with the “findclash” command. You can use it for multiple distance measurement in a single command. For example: open 2gbp findclash :lys@ca test self overlap -1000 log true … will measure all distances among lysine CA atoms in structure 2gbp and list results in the Reply Log (open from Favorites menu). The -1000 in the command says to measure the distance even if the atoms are “overlapping” by -1000 (more than 1000 angstroms apart). The last column in the results is the atom-atom distance, and they are given in order of increasing distance, in this case: 464 contacts atom1 atom2 overlap distance LYS 191.A CA LYS 189.A CA -1.802 5.562 LYS 227.A CA LYS 223.A CA -2.137 5.897 LYS 300.A CA LYS 246.A CA -2.800 6.560 LYS 169.A CA LYS 164.A CA -4.676 8.436 LYS 270.A CA LYS 276.A CA -4.677 8.437 [… several lines removed …] LYS 276.A CA LYS 203.A CA -53.705 57.465 LYS 276.A CA LYS 137.A CA -56.756 60.516 LYS 61.A CA LYS 137.A CA -56.829 60.589 LYS 58.A CA LYS 137.A CA -59.598 63.358 464 contacts The log contents can be saved to a text file, for example see <http://plato.cgl.ucsf.edu/pipermail/chimera-users/2008-October/003184.html> However, your log would have a huge amount of results for all structures and it might be hard to tell which results go with which structures, so another possibility would be to save a separate file of results for each structure, and in that case your script would need to substitute in an output filename, e.g. findclash :lys@ca test self overlap -1000 saveFile ~/Desktop/2gbp.log See findclash documentation for all the options. Then you can embed the command in the python looping script as described in the first link above. <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/findclash.html> 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 Aug 18, 2015, at 8:36 AM, Feixia <feixia.chu(a)unh.edu> wrote: > Hi there, > I am interested in retrieving distance information from large dataset in an automatic fashion. For instance, can we use Chimera to get the distances between lysine alpha-carbons of current PDB entries. Presumably, we can download all PDB structures on our local desktop, and just call functions one structure at a time. I wonder if we can do that with Chimera. Your advice will be highly appreciated. > Best, > Feixia

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measure the vertical distance between aromatic planes
by Wang, Bing 19 Aug '15

19 Aug '15

Hi Chimera, Is there a way to measure the vertical distance of two planes in the structure? I do know how to measure the angle between two planes or one line and one plane by the Axes/Planes/Centroids in Chimera. I don't need the distance of two centroid of two planes. I do need the vertical distance of two planes. Could you please show me in detail? Thanks a lot! Bing Wang

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