May 2017 - Chimera-users - RBVI Mailing Lists

scripting & density
by Dougherty, Matthew T 12 May '17

12 May '17

Hi, I have a dataset, its values are 1-255. I would like to modify the density values using a script. Specifically, I would like to set density values 50-74 & 90-110 to the value of zero. Is there a way to do that using scripting, or do I need to do that using python? Matthew Dougherty National Center for Macromolecular Imaging Baylor College of Medicine ================================================= =================================================

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surfaces
by Arthur Szabo 12 May '17

12 May '17

Working with a structure that has many domains. I would like to show the surface of three of the domains. I have hidden the ribbon residues of all but the ribbons of three domains. I receive the following error message [cid:image001.png@01D2CB26.2CA19B30] The domains are not contiguous in the structure, but even if I try to show the surface of only one domain I get the same message. And going to the Selection inspector is not helpful since it is not obvious as to how that option assists the surface representation. Over to you Thanks Arthur G. Szabo

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vop scale and vop morph (maybe chimeraX?)
by Oliver Clarke 11 May '17

11 May '17

Hi, When I morph two maps, if they have different mean/sd, I always have to scale the mean and sd of the second map to that of the first, otherwise the morph looks very non-linear - nothing happens until fraction 0.9, and then the morphing happens increasingly fast (so not ideal for visualization). If I normalize one map to the other I get a beautiful, smooth, linear morph. Would it be possible in either chimera or chimeraX to automate this? Either to add an option to vop scale to scale one map directly to the parameters of another (rather than having to use vop measure mapstats) or to have an option for vop morph to put both maps on the same scale? Cheers Oli

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suggestion: if clip planes cross, swap them?
by Oliver Clarke 11 May '17

11 May '17

Hi, Quite often, in aliases and scripts where I am adjusting the clip planes, I get the error “far clip plane placed in front of near clip plane”, or words to that effect. I’ve tried various ways to remedy this but it has to be done on a case by case basis and sometimes I just can’t figure it out. Would there be any possibility for Chimera to rather than triggering an error in such a case, just swap the clip planes when this happens, so the near plane becomes the far plane, and vice-versa? Or is there some other foolproof way to avoid this? I get this error when I want to adjust the hither and yon planes successively - would it be possible to add a command that adjusts them both at the same time, like `section` but with simultaneous independent control over both clip planes? Cheers Oli

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morph map fails with solid representation
by Oliver Clarke 10 May '17

10 May '17

Hi, When I create (using the latest nightly build) a morph between two maps using the “Morph map” GUI, and then I change the representation of the resultant volume to solid, the morph no longer runs, or rather, it appears to run, but the solid volume does not update. This used to work - I used it to create quite a few movies - so I guess it is a bug? Cheers Oli

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symmetrical fit of maps
by Oleksiy Kovtun 10 May '17

10 May '17

Hi all, is there is a way to do symmetrical fit and add symmetrical copies for map to map fitting? The standard symmetrical fitting protocol (measure symmetry. #0...; sym #1 group #0 update true; fitmap...) only works for molecule to map fit. Thank you, Oleksiy Dr Oleksiy Kovtun Research Fellow Briggs group MRC Laboratory of Molecular Biology Francis Crick Avenue Cambridge CB2 0QH UK Tel: + 44 1223 267551 Email: okovtun(a)mrc-lmb.cam.ac.uk

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translation and rotation in MATLAB using transformation matrices from chimera
by Oleksiy Kovtun 10 May '17

10 May '17

Dear all, I need to merge two maps in MATLAB using alignment data from chimera. Inputs: two maps of the same box size, origin. I use matrixget - to report translation and rotation matrices for the aligned map . Translation operation works well when transferred into MATLAB (briefly, translation matrix gets converted in eulers and pased on to tom_rotate command in MATLAB, TOM package). However the x y z translation coordinates (the fourth column top to bottom in matrixget - output) are way off the real translation when using tom_shift command in MATLAB, TOM. I found out that if I open the rotated map and fit it again, it gives close to correct translation matrix. What's going wrong here? Does anyone have a solution how to overlay 3D arrays in MATLAB using chimera-reported transformation matrices? Many thanks, Oleksiy Dr Oleksiy Kovtun Research Fellow Briggs group MRC Laboratory of Molecular Biology Francis Crick Avenue Cambridge CB2 0QH UK Tel: + 44 1223 267551 Email: okovtun(a)mrc-lmb.cam.ac.uk Dr Oleksiy Kovtun Research Fellow Briggs group MRC Laboratory of Molecular Biology Francis Crick Avenue Cambridge CB2 0QH UK Tel: + 44 1223 267551 Email: okovtun(a)mrc-lmb.cam.ac.uk

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Multiple fitting of structures in to EM densities
by Healey, Joe 10 May '17

10 May '17

Dear chimera team, I have a large EM density I would like to fully populate with a number of copies of a protein. To be more specific, the EM density is of 2 concentric protein rings (EMDB-6720), and each concentric ring is stacked 3 or 4 times. Each ring is a hexamer, so I would like to populate every single ring with 6 copies of each protein (but the inner and outer rings are 2 different proteins). What would be the best mechanism to iteratively import a protein, populate an EM density space, then move on to the next one? Currently, I think if I was to simply open several copies of the protein, they would probably all try to fit within the same EM density position, leaving the rest of the structure empty? My apologies if this isn't totally clear, I've tried to explain it as best as I think I can. I'm happy to accept solutions in 'chimera language', python (or I also have Jaime's Pychimera installed). Many thanks Joe Healey M.Sc. B.Sc. (Hons) MSRB PhD Student MOAC CDT, Senate House University of Warwick Coventry CV47AL Mob: +44 (0) 7536 042620 | Email: J.R.J.Healey(a)warwick.ac.uk Jointly working in: Waterfield Lab<http://www2.warwick.ac.uk/fac/med/research/tsm/microinfect/staff/waterfield…> (WMS Microbiology and Infection Unit) and the Gibson Lab<http://www2.warwick.ac.uk/fac/sci/chemistry/research/gibson/gibsongroup/> (Warwick Chemistry) Twitter: @JRJHealey<https://twitter.com/JRJHealey> | Website: MOAC Page<http://www2.warwick.ac.uk/fac/sci/moac/people/students/2013/joseph_healey> | ORCID: orcid.org/0000-0002-9569-6738

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Re: [Chimera-users] Wire thickness
by Oliver Clarke 10 May '17

10 May '17

Hi Hernando, I used the ca_and_sidechains alias in this script (you should be able to get the individual commands from that). https://github.com/olibclarke/chimera-trimmings/blob/master/chimera_aliases… Cheers Oli > Dear Chimera > How do you set the thickness of the backbone and side chains independently to produce figures like the ones below (sorry I hijacked the picture used in blurred-display discussion). > > Thanks > > H.

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Wire thickness
by Hernando J Sosa 10 May '17

10 May '17

Dear Chimera How do you set the thickness of the backbone and side chains independently to produce figures like the ones below (sorry I hijacked the picture used in blurred-display discussion). Thanks H. [cid:image001.jpg@01D2C8F6.BEA06B60][cid:image002.jpg@01D2C8F6.BEA06B60]

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Chimera-users May 2017