- Chimera-users - RBVI Mailing Lists

Color holes in mesh?
by Oliver Clarke 08 Apr '16

08 Apr '16

Hi, When I want to show electron density around, for example, a single alpha helix in a structure, there are a couple of options in chimera - one would be to use vop zone, which I don't like for this purpose, because it creates a new map that can be recontoured (so one can't see where the original map has been cut). The sop analog of this, sop zone, works quite well for the purpose, but there is no easy way that I can find to cap the holes that are created in the mesh - I want to do this so that I can make it obvious where "carving" the map has affected the shape of the resultant map, or has truncated connected regions that are not displayed. Would it be possible to add such an option in ChimeraX? Or having an option to represent the inside of a surface differently from the outside would do the trick also. For the moment I have a work around (used in the attached pic): 1. Create a mesh. 2. Duplicate the mesh, change to surface rep and set transparency to 0.001. 3. Create a copy of this surface, change the transparency to 0.99 and increase the volume level by 0.001. Cheers, Oli.

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Re: [Chimera-users] how to generate good STL code for atoms display
by Jakob Suckale 08 Apr '16

08 Apr '16

Hi David, Yep, you recalled that well despite the convoluted name. It does help with overall simplification but it does that for all structures proportionally and ribbons are well converted. It's just the atom models that are excessive. What I cannot do yet in Meshlab is get rid of all these pointless internal structures. The 5-membered ring in the attachment for example is full of invisible vertices inside that inflate the file size. There are ways to partially remove internal structures with Meshlab (http://bit.ly/1Tyzz1u) but they don't do a very good job because they typically remove some of the outer ribbon surfaces as well creating hole that need to be filled. All the best, Jakob On 7 April 2016 at 23:01, David Bhella <David.Bhella(a)glasgow.ac.uk> wrote: > I use meshlab for this I am not in front of my mac just now but from memory the filter is quadratic edge collapse decimation (or something like that). It works well to reduce the poly count. > E-mail me if you want help trying it. > Another useful tool is netfabb to repair stl files by removing unwanted shells and fixing non-manifold maps. Lately I have found surfaces from chimera don't suffer from this as much as they used to.... > > Sent from my iPad > >> On 7 Apr 2016, at 21:17, Greg Couch <gregc(a)cgl.ucsf.edu> wrote: >> >> Hi Jakob, >> >> One way to reduce the number of STL triangles generated is to lower the subdivision amount in the graphics quality section of the Effects dialog in Chimera. >> >> Another way is to load the STL output into the open-source MeshLab program, http://meshlab.sourceforge.net/, and use its tools to simplify the mesh. I have not that, so if someone has done that, please chime in, and describe which MeshLab filters to use. >> >> You may need to use both techniques to make 3D printer software work. If your 3D printer takes VRML input, I would recommend using Chimera's VRML output instead. >> >> HTH, >> >> Greg >> >>> On 04/04/2016 05:13 AM, Jakob Suckale wrote: >>> Sorry, the message was truncated. This is the missing part. >>> >>> A netfabb repair of the chromophore STL does significantly simplify >>> the model and reduce the file size from 13.7 to 5.7 MB indicating that >>> there's a lot of room for improvement in the STL export esp. of atom >>> models. >>> >>>> On 4 April 2016 at 11:54, Jakob Suckale <jakob.suckale(a)uni-tuebingen.de> wrote: >>>> Dear chimeras, >>>> >>>> Does anybody know of a good way to generate lean STL code for atom/bond display? >>>> >>>> Take this example. I'm generating STLs to 3D print GFP. Exporting the >>>> ribbon of the beta barrel generates an ok STL of 6.8MB. However, >>>> exporting the wire atom display of the chromophore generates a >>>> horribly inflated STL of 13.7MB - almost twice the ribbons file >>>> despite the tiny size (see screenshot attached). Printing the >>>> chromophore is problematic since it contains a lot of weird internal >>>> structures instead of being a clean surface model of the wireframe. A >>>> netfabb repair of the chromophore STL >>>> >>>> Looking forward to your expert ideas. >>>> >>>> All the best, >>>> >>>> Jakob >>>> >>>> >>>> >>>> Jakob Suckale, PhD >>>> Lecturer in Biochemistry >>>> University of Tübingen >>>> +49-7071-29-73363 >>> _______________________________________________ >>> Chimera-users mailing list: Chimera-users(a)cgl.ucsf.edu >>> Manage subscription: http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users >> >> _______________________________________________ >> Chimera-users mailing list: Chimera-users(a)cgl.ucsf.edu >> Manage subscription: http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users

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how to generate good STL code for atoms display
by Jakob Suckale 07 Apr '16

07 Apr '16

Dear chimeras, Does anybody know of a good way to generate lean STL code for atom/bond display? Take this example. I'm generating STLs to 3D print GFP. Exporting the ribbon of the beta barrel generates an ok STL of 6.8MB. However, exporting the wire atom display of the chromophore generates a horribly inflated STL of 13.7MB - almost twice the ribbons file despite the tiny size (see screenshot attached). Printing the chromophore is problematic since it contains a lot of weird internal structures instead of being a clean surface model of the wireframe. A netfabb repair of the chromophore STL Looking forward to your expert ideas. All the best, Jakob Jakob Suckale, PhD Lecturer in Biochemistry University of Tübingen +49-7071-29-73363

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3D viewing
by Mohamed Noor 07 Apr '16

07 Apr '16

Dear all Where can I find information on the hardware required for 3D viewing with Chimera? I am building my Linux system, so I would appreciate useful pointers. 1. IIUC, I need a Quadro card as this does not work with GeForce. What should I look for when selecting a suitable card? 2. I want to also have a second monitor. Since this is not going to be used for 3D, can I just hook up any normal monitor? Or do both monitors have to be the same model etc.? 3. I have read that I need to have a card with 3-pin DIN port. Is this true? Thanks. Mohamed

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Advice on SASA
by George Tzotzos 07 Apr '16

07 Apr '16

I have a couple of questions on Chimera’s implementation of SASA. First, I’ll try to explain briefly my problem and then ask the questions. My protein is a homodimer. There exist 3 X-ray structures of the protein in complex with serendipitous ligand as well as in complex with biological ones. The ligands bind at the interface between the two chains of the homodimer. It is not clear whether dimer formation is a crystallographic artefact. Biochemical experiments are likewise inconclusive. It has been argued that the biological ligands may stabilise the formation of the dimer. Furthermore, it has been argued that upon ligand binding some of the interface residues become buried. I’ve conducted extensive MD simulations with and without the biological ligands. I would like to test whether ligand binding has an effect on the SASA of the interface residues. 1. Can I restrict measurement of SASA to selected residues only? In other words, can I use a mask specifying the residues of interest? 2. From the documentation, I understand that the Chimera implementation of SASA is applied on single pdb structures and not on trajectories. If I use representative structures from MD clusters, should I strip the ligand before measuring SASAs? Thank you in advance for your suggestions and apologies for the long-winded explanation. Best regards George

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save gaussian volume filter as a new map?
by H. Adam Steinberg 06 Apr '16

06 Apr '16

Hi All, How do I save a map that I applied a gaussian volume filter to? I opened a cryo EMD map and then applied a gaussian volume filter to it with a width of 1.5 to clean up some of the extra detail. I would now like to save that map out of Chimera to use elsewhere. When I save the Chimera file it says “EMD-6413.map gaussian was not saved with the session.To have them included in the session it must be saved in separate volume files before the session is saved.” How do I do that? <http://www.artforscience.com/> <http://www.artforscience.com/>H. Adam Steinberg Artist & Scientist 7904 Bowman Rd Lodi, WI 53555 608/729-5944 <http://www.artforscience.com/>artforscience <http://www.artforscience.com/> Facebook <http://facebook.com/artforscience1> Twitter <http://twitter.com/artforscience> McPherson Eye Research Institute <http://www.vision.wisc.edu/>

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Adding 3D arrows (vectors) in a scene
by Henrique C. S. Junior 05 Apr '16

05 Apr '16

Dear list, Magnetic Anisotropy is a directional property and, because of that, it is useful to repreent it as a vector that crosses the molecule. Is that a way to add 3D "arrows" (vectors) using Chimera? -- *Henrique C. S. Junior* Químico Industrial - UFRRJ Mestrando em Química Inorgânica - UFRRJ Centro de Processamento de Dados - PMP

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B-weighted map
by Quentin Vicens 05 Apr '16

05 Apr '16

Hi folks, Would anyone know whether B-factor weighted maps can be calculated in Chimera? For example as an option to molmap or another tool. The goal would be to look at the correlation between a pdb and a map using "fit in map" but by taking B-factor info into account. Thanks! Quentin Quentin Vicens University of Strasbourg, France National Center for Scientific Research

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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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