August 2019 - Chimera-users - RBVI Mailing Lists

Morphing, ligands, and secondary structure
by Yan Kung 06 Aug '19

06 Aug '19

Hi Chimera, I’m a new-ish user, and I’ve found that morphing structures is usually very straightforward and easy to use. But I’m now running into an issue with morphing and ligands (and secondary structure). I’d like to make a single morph composed of states A-B-C-B-A (so 4 movements between 5 states). These movements are: (1) A-B: domain opens, (2) B-C: a ligand flies out, (3) C-B: the same ligand flies back in, and (4) B-A: domain closes. First problem: the ligand does not appear in the resulting morph, a problem suggested by the documentation, which I have tried (and failed) to solve using the tips I found in archived posts from this mailing list. Also, because the ligand has to fly in and out, I can’t simply superimpose the ligand from any of the individual states over the morph. So I tried a workaround: make each movement a separate morph. This works for movements 2 and 3 (where the ligand flies out and in). But the ligand still does not appear in movements 1 and 4 (where the ligand remains in place and the domain moves). I’m not sure why the ligand’s appearance would depend on whether it flies in/out, or whether a domain moves… But it seems to. Moreover, a second problem emerges that has to do with secondary structure and is difficult to explain. (Essentially: a few protein regions are on the border between helices and loops such that they appear as helices in some states but as loops in others, and vice versa. If possible, I’d like the secondary structure to remain constant across all states, or else it’s distracting. Even still, I’ve tried to embrace this and use ksdssp to show the helices/loop switching back and forth, but this is distracting as they flicker between helices and loops, each region at its own separate frame. Specifying ksdssp only in certain frames to minimize the flickering doesn’t work either, as different regions switch back and forth at different times.) The only solution I can think of that would maintain the same secondary structure throughout is to just make a single morph of all movements (and not use ksdssp). But this puts me back where I started! Any ideas? (Separately, I realize that I could make a simpler morph of just A-B-C, then record it as “roundtrip”, i.e. forward and backwards, to achieve the same thing as A-B-C-B-A. But this doesn’t solve the problems above.) Thanks very much, Yan -- Yan Kung Assistant Professor Department of Chemistry Bryn Mawr College http://www.brynmawr.edu/people/yan-kung Follow: @KungLab<https://twitter.com/KungLab>

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Nvidia 3D Vision on a large display
by Tom Goddard 02 Aug '19

02 Aug '19

Krish Raman asked what kind of large displays might work with Nvidia 3D Vision stereo glasses with Chimera. Hi Krish, I believe any display capable of a high refresh rate, at least 120 Hz (even 100Hz would do) will be able to show stereo with Nvidia 3D vision. Conventional 60 Hz displays could only show stereo at 30 Hz in each eye (since the display first shows the left eye, then shows the right eye in sequence), and 30 Hz is too slow causing flicker. Video gaming displays are usually advertised as 144 Hz and I believe any of those would work. It is hard to find big displays at 144 Hz, but here is an example, 49 inch ultra wide Samsung CHG90 https://www.amazon.com/Samsung-49-Inch-Curved-Monitor-LC49HG90DMNXZA/dp/B07… <https://www.amazon.com/Samsung-49-Inch-Curved-Monitor-LC49HG90DMNXZA/dp/B07…> If one person is using this sitting at a desk it is very wide and would probably give very nice immersive stereo because of the width. It is not ideal for your use with an audience standing further back because of its extreme 32:0 aspect ratio. You could look for a video gaming TV, such as these https://www.tomsguide.com/us/best-4k-gaming-tv,review-4837.html <https://www.tomsguide.com/us/best-4k-gaming-tv,review-4837.html> Keep in mind your Nvidia 3DVision system may not work with any of these. I would strongly recommend testing at a store with your 3DVision before buying. Stereo is an an extremely obscure niche product and there is no telling if it will work without testing. Another option is to use a high refresh rate projector. That is what we use at my lab -- (ours is a $50,000 Christie, so I don't recommend it). Also I am sure you are aware that Nvidia discontinued support for 3D Vision and it will not work with any Nvidia drivers released after April 2019. So the 3D Vision system is going to be dead soon. Tom

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crash on using Preset Publication 2
by Dieter Blaas 02 Aug '19

02 Aug '19

Hi, I have been using the Publication Preset 2 for making figures of a number of pdb structures without problems. However, I now have a pdb that shows up well in Chimera and does not have any obvious problems. However, when trying rendering it with the Preset Publication 2 (and only with this one) Chimera crashes with the error message below: *** stack smashing detected +++: /home/blaas/.local/UCSF-Chimera64-1.10.2/bin/python2.7 terminated Since I have prepared the other figures with this setting I'd like using it as well for the next figure but how? Thanks a lot, best regards, 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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Chimera Viewdock Bug
by Sacco, Michael 02 Aug '19

02 Aug '19

Hello all, I would like to report a bug. When using Chimera in dual monitor mode on windows OS and loading the viewdock module, Chimera becomes unresponsive. However, when the second monitor is unplugged, it functions normally. I have confirmed this on multiple computers. After force closing Chimera a pop-up appears with the message "Chimera exited abnormally; the exit code was: 1.". Thanks everyone! Michael

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OBJ files are exported too small and won't open on other programs.
by Josh Moon 01 Aug '19

01 Aug '19

Hello! I am a relatively new and inexperienced user of Chimera. I am having a difficult time working with obj files. The Scenes I'm exporting as obj's end up having a very small file size (67 bytes in one case) and are being processed very quickly. The resulting file won't open successfully on any program that should understand an obj. Stl's are fine. Conversely, when I try to open an obj file into Chimera, it asks me to manually "Designate the File Type" as though it doesn't know what to do with it. Can someone please suggest what features I'm missing so that I can successfully export an OBJ? I'm also interested in how best to handle color information. Thank you! Josh ----------------------------------------- Josh Moon, Ph.D. (he/him/his) Educational Technology Specialist Kalamazoo College (269) 337-7415

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