November 2013 - Chimera-users - RBVI Mailing Lists

Constrainted fitting
by Christoph Wigge 22 Mar '19

22 Mar '19

Dear all, I would like to fit two protein monomers that form a dimer into an em density map. I know from previous mutagenesis studies that the binding takes place with two tryptophan residues and the counterpart binding pocket. How can I set this interaction as fixed so that chimera fits the rest of the molecule according to the density map without continuously changing this part of the essential protein protein interaction? I would like to fit that interaction manually and then exclude it from the automatic procedure. Thank you very much in advance. Bests Christoph Wigge

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volume planes tool
by Jeff Triffo 22 Jun '16

22 Jun '16

hi folks, anyone know if the volume plane tool will support arbitrary orientation of the plane any time soon? -Jeff

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Re: [Chimera-users] Display a spider volume data in a specific orientation
by Elaine Meng 08 May '14

08 May '14

Hi Zongli, This is not my area of expertise (our expert is currently out of town) -- at first I thought you could use "Transform Molecule Coordinates" (under Tools... Movement), but now I see that it works only on atomic structures rather than maps: <http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/transform/transfor… > It only works on molecular structures because it actually changes the atomic coordinates, without changing the model transformation. I've figured out one workaround, but it is both crazy and slightly tedious: (1) open your map (say as model 0). (2) open any atomic-resolution structure, it doesn't matter what, and open it twice -- now you have three models. Don't move them separately from the map (yet). Let's say the atomic structures are models 1 and 2. (3) use "Transform Molecule Coordinates" with desired Euler angles and shift on one copy of the atomic structure (say model 1). (4) use the match command to superimpose the other copy of the atomic structure on the one that was transformed: match #2 #1 (the command can use the whole models since they should have exactly the same atoms) (5) use the matrixcopy command to apply the transformation matrix of the second copy of the atomic structure to the map: matrixcopy 2 0 You might think "why do I need two copies of the atomic structure? can't I just transform one copy and then use matrixcopy?" ... in fact that's what I tried first, but after it didn't work, I realized it was because the Transform tool works by changing the coordinate values and not the stored matrix of the model. It is necessary to match the second copy to generate a corresponding matrix, and then matrixcopy can be used. I'm CC-ing the chimera-users(a)cgl.ucsf.edu list in case other Chimera users have suggestions. Our expert Tom G should be back next week and he might also have ideas. In general, it's better to send Chimera questions to that mailing list instead of just me, because I could be away from work or (like now) lacking a good answer! 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 Apr 7, 2010, at 11:51 AM, Li, Zongli wrote: > Hi Elaine, > I have a spider volume data (or mrc density map) from which I got a > serious 2D projections. I have the Euler angles for each projection. > Is there a way in Chimera that I can use those Euler angles to > display the 3D spider volume data (or mrc density map) in a specific > orientation that corresponding to that 2D projection? > Thank you very much in advance. > Best, > Zongli > > **************************************** > Zongli Li, Ph.D. > > Howard Hughes Medical Institute > Department of Cell Biology > Harvard Medical School > C Building, Room 420B > 240 Longwood Avenue > Boston, MA 02115 > > Tel: 617-432-4095 (Office) > 617-432-4708 (EM Suite) > 617-432-4091 (Computer room) > Fax: 617-432-1144 > Email: zongli_li(a)hms.harvard.edu > *************************************** >

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Information
by Mabel Guzman Rodriguez 02 Dec '13

02 Dec '13

Hello! I few days ago I tried to use your program Chimera, the reason is because I try to make a structure of a multimer protein but I need to know how can I bond the single subunits of the protein to make an hexamer. I hope you can help me. Greetings Mabel G.

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Query about increasing resolution for vrml export
by Darren Gowers 02 Dec '13

02 Dec '13

Dear Chimera community, Sorry to bother. I'm very interested in trying to increase the vrml export resolution (of any pdb model) so that more polygons are used to describe the curvature of the electron density more smoothly. There is a command in PyMol that does the equivalent (I think it is 'surface_quality'), but I'd rather use Chimera to generate vrml files! Does anyone have any suggestions how to make molecular surfaces much smoother please? Many thanks, Darren -- Dr Darren Gowers<http://www.port.ac.uk/departments/academic/biology/staff/title,30538,en.html> Senior Lecturer in Biochemistry School of Biological Sciences University of Portsmouth PO1 2DY +44(0)2392 842057

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Re: [Chimera-users] solvent-accessible surface area
by Amit Goyal 02 Dec '13

02 Dec '13

Hi Elaine, Today I subscribe to Chimera mailing list, but unable to get the proper way to post a query on it. So I am sending the query this way. I have been reading this post about how to get the areaSAS and areaSES values for any residues. http://www.cgl.ucsf.edu/pipermail/chimera-users/2008-May/002617.html Still, I think, is there any specific values/range for the areas AS to decide whether a particular amino acid residues is buried or exposed to the solvent. Hoping for Thanks for your help. Sincerely, AMIT -- AMIT GOYAL, Pusan National University, Korea south. amitgsir(a)pusan.ac.kr

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colouring according to hydrophobicity
by Dieter Blaas 29 Nov '13

29 Nov '13

Hi, I am wondering whether there is any (easy) way of colouring a volume (e.g. an MRC file made from a pdb file and filtered to say, 10 A with e.g. xmipp) according to hydrophobicity (using the values derived from the amino acid residues in the pdb file)? I am aware of the way to colour the van der Waals surface but the resolution is somewhat too high not allowing to get a more general view, for example whether the molecule is more hydrophobic on one side than on another side. The same question applies to the charge distribution.... Thanks, Dieter -- ------------------------------------------------------------------------ Dieter Blaas, Max F. Perutz Laboratories Medical University of Vienna, Inst. Med. Biochem., Vienna Biocenter (VBC), Dr. Bohr Gasse 9/3, A-1030 Vienna, Austria, Tel: 0043 1 4277 61630, Fax: 0043 1 4277 9616, e-mail: dieter.blaas(a)meduniwien.ac.at ------------------------------------------------------------------------

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Overlay binding sites
by Markus Heller 28 Nov '13

28 Nov '13

Hello all, I'm pretty sure this has been done before, so before re-inventing the wheel or failing miserably and doing everything by hand, I thought I'd ask here first :) I have a protein that has been crystallized with about a dozen ligands of different sizes. I'd like to overlap the protein residues forming the binding site. My plan was to pick the 2 largest ligands, select all protein residues within say 7 A, and consider these to be the residues forming the binding site. Then, I'd like to match this set of residues for all proteins to the same reference. I suppose I could do this all manually, but I'm hoping that there is a quicker, more efficient way! Any tips are appreciated! Thanks and Cheers Markus -- Markus Heller, Ph.D. NMR Scientist CDRD - The Centre for Drug Research and Development 2405 Wesbrook Mall, Fourth Floor | Vancouver, BC V6T 1Z3 | Main: (604) 827-1147 Direct: (604) 827-1122 | F: (604) 827-1299 | E: mheller(a)cdrd.ca<mailto:mheller@cdrd.ca> | www.cdrd.ca [cid:image007.png@01CEEC32.879D5C80] Follow us: [Description: cid:image003.jpg@01CD86A6.39B41A10] <https://twitter.com/C_D_R_D> [Description: cid:image005.jpg@01CD86AE.B197F5D0] <http://www.linkedin.com/groups/CDRD-3186016/about?report%2Esuccess=3NcE4iZo…> [Description: cid:image009.png@01CD86AE.B197F5D0] <https://www.facebook.com/pages/The-Centre-for-Drug-Research-and-Development…> [Description: cid:image010.png@01CD86AE.B197F5D0] <http://www.youtube.com/user/CDRDCVI?view_as=public> This email and any files transmitted with it are confidential and intended solely for the addressee. If you are not the named addressee you should not disseminate, distribute, copy, or alter this email.

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features/question: stereo3d and volume rendering
by Dougherty, Matthew T 28 Nov '13

28 Nov '13

1) I have been doing S3D animations. One of things I am realizing is that I need to frequently adjust the interaxial and screen distances. Sometimes my IA might be 1mm or it might be 23 inches depending on the shot. Currently chimera does not maintain this camera metadata, so every session I need to reset the values which makes my animations slightly different. Since rendering can take several hours, one typo can trash the effort. Any suggestions on a workaround? There is also a linkage between IA, horizontal field of view, and screen distance, sometimes I think I get caught in a hysteresis loop trying to converge to the desired shot. As a note, I pretty much stopped using the zoom and have gone to dolly, keeping the scale to one. 2) when doing volume rendering of electron tomograms I am finding it useful to load the same mrc map file in multiple times, such that each model has a different transfer function relating to different densities or structures. I can currently load seven, but four must be changed from floating point to byte in order to prevent memory lockout thrashing, error messages, etc. Is there a way to load a single map file in and have multiple models and transfer functions for the solid viewing? Matthew Dougherty National Center for Macromolecular Imaging Baylor College of Medicine

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Protonation of selected atoms ?
by Marek Maly 28 Nov '13

28 Nov '13

Dear all, I would like to protonate just several nitrogen atoms (tertiary amines) of my hyperbranched polymer. I tried Structure "Editing -> Add hydrogens" but it protonised all my tertiary amines in the structure ignoring the fact that only few of them were selected and considered for protonation. So is there any way how to protonate only selected N atoms ? If not would be a good idea to add this possibility into Add Hydrogens panel (function). Thank you, Best wishes, Marek -- Tato zpráva byla vytvořena převratným poštovním klientem Opery: http://www.opera.com/mail/

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