- Chimera-users - RBVI Mailing Lists

on contact surface and domain angle
by Smith Liu 04 Apr '16

04 Apr '16

Dear All, Will you please tell me the command to calculate the contact surface area between 2 sub-units in the protein complex? Will you please also tell me the command to calculate the angle in degree between 2 domains in a subunit? Smith

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ACA 2016 SAS Workshop
by Kushol Gupta 02 Apr '16

02 Apr '16

On behalf of the organizing committee, I am pleased to announce a workshop on "Computational Approaches to the Structural Modelling of Biological Macromolecules using Small Angle Scattering." This workshop will take place on Friday, July 22nd, 2016 at this year's American Crystallographic Association (ACA) Meeting in Denver, Colorado, U.S.A. The meeting itself will run from July 22-26. WK.02 Computational Approaches to the Structural Modelling of Biological Macromolecules using Small-Angle Scattering. This one-day workshop will focus on computational approaches to structural modelling and analysis. In the first session, a brief reprise of fundamental concepts will be provided, with a focus on pitfalls in data acquisition and reduction that can affect subsequent data analysis and modelling. The remainder of the day will be allocated to the hand-on application of the leading software packages to the analysis of solution scatter. This workshop will feature direct participation from the creators of the most prevalent software packages currently used (including BIOSAXS(EMBL), SIBYLS, CCP-SAS, FoXs and IMP). The participating groups will present their software, including the basis for the algorithms employed, and further deliver guided hands-on tutorials for workshop participants. This approach will introduce and train participants on the appropriate application of these tools, including experimental design, model preparation, comparison of structural models using both SAS and complementary information, validation, and most importantly the limitations of interpretation with regards to the biological conclusions that can be made. The workshop format will include lectures, and a selection of hands-on practical exercises. Students will be expected to bring laptops with appropriate pre-installed software as necessary. Prior to the workshop, a website will be made available containing installation instructions and software for each tutorial. Tentative Program Schedule Basic Theory and Methods Joint Session 8:00 am - 9:30am - Introduction: what is SAS data good for? (short) - Theory Essentials: How to get your scattering profiles - SAXS and SANS: common pitfalls, how to ensure the data is suitable for modelling - Cross Checks and Validation 9:30 AM - 10:00 AM Coffee Break Software Application and Tutorial Session 10 am - 7pm 10:00 AM - 11:30 AM BIOSAXS(EMBL) lectures and guided tutorial 11:30 AM - 12:30 PM Lunch and Discussions (vendor presentations in the form of 'lunch and learn') 12:30 PM - 2:00 PM IMP Lectures and Guided Tutorial 2:30 PM - 3:00 PM Coffee Break 3:00 PM - 4:30 PM SIBYLS lectures and guided tutorial 4:30 PM - 6:00 PM CCP-SAS lectures and guided tutorial 6:00 PM - 7:00 PM Discussion Pre-registration is mandatory. The fee to attend is: . Student (undergrad, grad or postdoctoral) - $140 . Corporate - $275 . Non corporate or non student - $140 Lunch will be included. Organizers: . Angela Criswell Rigaku Americas Corporatio Angela.Criswell(a)rigaku.com . Richard Gillilan Cornell CHESS reg8(a)cornell.edu . Kushol Gupta Perelman School of Medicine, University of Pennsylvania kgupta(a)upenn.edu . Michal Hammel SIBYLS group at The Advanced Light Source (ALS) mhammel(a)lbl.gov . Susan Krueger NIST Center for Neutron Research/CCP-SAS susan.krueger(a)nist.gov . Maxim Petoukhov BIOSAXS group at the European Molecular Biology Laboratory (EMBL) maxim.petoukhov(a)embl-hamburg.de . Adam Round EMBL Grenoble around(a)embl.fr . Dina Schneidman Institute of Life Science, Hebrew University of Jerusalem dina.schneidman(a)mail.huji.ac.il . Jill Trewhella University of Sydney jill.trewhella(a)sydney.edu.au More information is available at: http://www.amercrystalassn.org/wk.02-saxs http://www.amercrystalassn.org/2016-meeting-homepage Kushol Gupta, Ph.D. Research Assistant Professor Department of Biochemistry and Biophysics Perelman School of Medicine at The University of Pennsylvania <mailto:kgupta@upenn.edu> kgupta(a)upenn.edu / 215.573.7260 / 267.259.0082 / <http://www.stwing.upenn.edu/~kgupta> www.stwing.upenn.edu/~kgupta

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mcopy for maps?
by Oliver Clarke 01 Apr '16

01 Apr '16

Hi all, is there an equivalent command to mcopy for maps? I find mcopy really handy for copying display settings from one molecule to another, would be great to have a similar facility for maps - maybe it already exists and I can't find it? Cheers, Oli

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buriedArea calculation: MSMS vs Chimera
by Bala subramanian 01 Apr '16

01 Apr '16

Friends, I have a task to calculate how much is the buried SASA during formation of a bi-domain protein. The usual relation to obtain is (SAS-domain1 + SAS-domain2) - SAS-complete I have a difficulty to understand how the calculation is performed in Chimera. As a test case, i used the 1crn.pdb and performed using MSMS and in Chimera. *MSMS calculation* (Input: msms -if 1crn.xyzr -probe_radius 1.5 -density 3.0) Complete system SAS = 3054.258 , (residue 1-23) pA = 2143.122 , (residue 24-46) pB = 2324.809, hence total buried = ( pA + pB) - 3054.258 = 1413.673 *Chimer calculation* surf #0 (Reply log: SAS = 3022.61) measure buriedArea :1-23 :24-46 probeRadius 1.5 vertexDensity 3.0 Status line : SAS = 697.876, SES = 423.938 Reply log: *Buried solvent accessible surface area* B1SAS = 681.191, B2SAS = 714.56, BaveSAS = 697.876 (A1 = 2116.11, A2 = 2302.43, A12 = 3022.79 = 1434.92 + 1587.86) I am not getting the calculation (and the motive as well) of the BaveSAS in the following part of the code. q1) What is Chimera actually doing here q2) Which one i should report, raw buried SAS or BaveSAS in your opinion ? ---------------------------------- for ai,a in enumerate(atoms1): a.buriedSESArea = aareas1[ai,0] - aareas12[ai,0] a.buriedSASArea = aareas1[ai,1] - aareas12[ai,1] ases121 += aareas12[ai,0] asas121 += aareas12[ai,1] for ai,a in enumerate(atoms2): a.buriedSESArea = aareas2[ai,0] - aareas12[n1+ai,0] a.buriedSASArea = aareas2[ai,1] - aareas12[n1+ai,1] ases122 += aareas12[n1+ai,0] asas122 += aareas12[n1+ai,1] careas1, careas2, careas12 = s1[4], s2[4], s12[4] ases1, asas1 = area_sums(careas1) ases2, asas2 = area_sums(careas2) ases12, asas12 = area_sums(careas12) bsas1 = asas1 - asas121 bsas2 = asas2 - asas122 bsas = 0.5 * (bsas1 + bsas2) bses1 = ases1 - ases121 bses2 = ases2 - ases122 bses = 0.5 * (bses1 + bses2) Thanks, Bala -- C. Balasubramanian -- C. Balasubramanian

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how to fit the em density map of crystal
by Yaowang Li 01 Apr '16

01 Apr '16

Dear all, I am thinking about how to fit the EM density map of crystal. cryo-EM images of crystal were collected and reconstructed to a map, but with a poor resolution(around 7A). In this condition, which is the best way to fit the map? Best Regards, Yaowang LIC, Leiden University

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Issues loading RESTServer extension on Headless Linux installation
by tom＠pine-biotech.com 30 Mar '16

30 Mar '16

Hi all, Using the unsupported headless linux x64 installer, chimera-1.10.2-linux_x86_64_osmesa.bin, I can run Chimera at the command line but am having a very difficult time running the RESTServer extension. Using my ~/.chimera/preferences file from my OS X install where a location for Extensions was selected in the preferences and saved, and copied to linux and edited to contain the /opt/UCSF/Chimera64-1.10.2/share location instead, it does open a bunch of packages on start, unlike before when it refused to load any extension. However, it still cannot start RESTServer. [root@dfw share]# chimera Package "DBPuppet" already exists and tool(s) in it will not be loaded [snip, for full output see http://pastebin.com/s3GH7mbz ] > start RESTServer Starting extension 'RESTServer' failed As such, the one reason I wanted to run Chimera headless on linux does not seem to work. I know it's unsupported so I'm not expecting anything, but perhaps this is something that can be resolved simply. I've done a few fruitless google searches and this mailing list kept coming up. Thanks for your time, Tom

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RR Distance to make a Difference Plot
by Edward J Brignole 30 Mar '16

30 Mar '16

Dear Chimera folks, I've been looking into making Difference Distance Matrix Plots (a la Richards & Kundrot, Proteins 1988) to evaluate domain movements between two models. Chimera's RR Distance plots get most of the way there and since they start from sequence alignments do a nice job handling different patches of missing residues between the two models. In addition to plotting Avg and Std Distances would it be possible to compute the differences between RR distances of two structures. Or if you don't want to implement this function in the RR Distance GUI, at least some sort of python script that could access the distance matrices from the RR Distance function and direct that to some sort of output either with matplotlib or the data as text to plot with another program. Thanks for considering it, Ed

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How to calculate the angle between two helix in a protein structure
by Elaine Meng 30 Mar '16

30 Mar '16

> Date: Wednesday, March 30, 2016 9:20 AM > Subject: How to calculate the angle between two helix in a protein structure > > Dear community, > > I want to calculate the angle between two helix in a protein structure. Does anybody know how to calculate it precisely? > Please help me. Thanks a lot. > > Best regards, > Bing Wang > National Institute of Biological Sciences, Beijing Dear Bing Wang, It can be done either with graphical interfaces (tool dialogs) or with commands. You can calculate and display helix axes with the Axes/Planes/Centroids tool (in menu under Tools… Structure Analysis) or the “define” command. The axes objects will be listed in in a dialog, and you can measure the angle between any two by choosing them in the dialog with the mouse, or by specifying their identifiers (as listed in the dialog) in the “angle” command. See manual pages: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/structuremeas/str…> <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/define.html> <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/angle.html> Example commands (start Command Line from the Favorites menu): open 2gbp define axis perHelix true angle a3 a10 This reports in the Reply Log (open from Favorites menu) that the angle between a3 and a10 is 22.893 degrees. The dialog shows that I have axes a1-a10 calculated from the 10 helices in the structure 2gbp. 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 P.S. Chimera questions should be sent to the chimera-users email address CC’d here… looks like you accidentally sent the question to just “chimera” instead

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Automatic Bond Rotating Script
by Lisa Rohrwasser 29 Mar '16

29 Mar '16

Hello, I am currently trying to write a python script to rotate different bonds automatically many many times. The idea is to randomly chose a bond of a .pdb-File and rotate it by a certain angle. In principle the command line tool "rotation" is exactly what I would like to use, but i have difficulties implementing it. To start with rotating only one bond I already got: import chimera from chimera import runCommand as rc opened = chimera.openModels.open('~/Documents/rho.pdb') #open protein rho = opened[0] #get random bond (it is set to bond 10 for now) b = rho.bonds[10] #gives back both atoms corresponding to the bond (atom IDs are needed for command line tool "rotation") b.atoms #select bond-atoms a1 = b.atoms[0] a2 = b.atoms[1] #now i would like to use command line tool "rotation", which gives many errors rc("rotation a1 a2 <angle>") So i think the problems are 1) objects a1, a2 have the wrong datatype 2) rc does not have access to a1, a2 Now i wonder if there is a solution at all to these problems or if i have to think of a completely different way? Thanks in advance, Lisa

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ribbackbone
by Edward J Brignole 29 Mar '16

29 Mar '16

Dear Chimera developers and users, I'm trying to make a figure that shows hbond contacts with a ligand but am having a problem displaying contacts while simultaneously displaying residues and ribbons. I know that ribbackbone will allow simultaneous display of ribbon and backbone, but the problem is that this attribute is set for the entire model, not per residue. To keep the display as uncomplicated as possible I want to just show side chains except when there's a backbone contact then I want to show backbone for that residue as well. The problem arises when contacting residues are adjacent, if ribbackbone is on, then the CA's are connected, but if I turn ribbackbone off then I lose the backbone atoms I'd like to show except an occasional floating carbonyl oxygen. My workflow is basically: sel #0:LIG findhbond spec #0 sel cross intermodel F intraMol F intraRes F makePseudobonds T reveal T distSlop 0.7 angleSlop 40 ac cs ribbackbone #0 transparency 75,r #0 I'm sure there's a way to accomplish this but I haven't been able to figure it out. I saw there has been some discussion previously on the chimera-users list about ribbackbone display but I didn't find any posts that would solve this particular problem. My apologies if this situation has already been discussed. Thank you for your help, Ed

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