August 2010 - Chimera-users - RBVI Mailing Lists

volume viewer question
by Boaz Shaanan 25 Aug '10

25 Aug '10

Hi William, The way I go about the sigma level contouring in Chimera, though it's somewhat ham-fisted but perhaps less complicated than Tom's suggestion, is to contour the region of interest at the desired sigma level in Coot or O and then play with the contouring in Chimera until both maps look as similar as possible (the maps rarely look identical for technical differences in the contouring techniques, I think). It works. Cheers, Boaz Boaz Shaanan, Ph.D. Dept. of Life Sciences Ben-Gurion University of the Negev Beer-Sheva 84105 Israel Phone: 972-8-647-2220 ; Fax: 646-1710 Skype: boaz.shaanan‎

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volume viewer question
by William Snee 25 Aug '10

25 Aug '10

Hello, I am trying to make an electron density figure using chimera and need to contour the F0-Fc map to 3 sigma. How can you determine the sigma level displayed with the volume viewer? The levels appear to be different than that observed when using coot or Xtalview. Thank you, William Snee

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Chimera and Sparky
by Hagn, Franz 24 Aug '10

24 Aug '10

Dear all, I am trying to run Chimera connected to Sparky for NMR NOE visualization. I am using the latest Sparky MacOSX distribution (for 10.4) and the last built of Chimera which came out today on a MacOSX 10.6 Intel. When I start Chimera within Sparky, I get a bunch of error messages. Does anybody know which Chimera runs with the latest Sparky? Thanks, Franz -- Franz Hagn, Ph.D. Department of Biological Chemistry & Molecular Pharmacology, Room C1-103 Harvard Medical School 240 Longwood Ave, Boston, MA 02115 Tel: +1(617)432-3211 Fax: +1(617)432-4383 --- Franz Hagn, Ph.D. Department of Biological Chemistry & Molecular Pharmacology, Room C1-103 Harvard Medical School 240 Longwood Ave, Boston, MA 02115 Tel: +1(617)432-3211 Fax: +1(617)432-4383

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ValueError: dimensions too large
by Josh Kacher 24 Aug '10

24 Aug '10

I am trying to use the volume eraser, but whenever I click erase, I get a Chimera Error box come up that says: ValueError: dimensions too large. File "C:\Program Files\Chimera\share\VolumeViewer\volume.py", line 1085, in region_grid m = zeros(shape, d.value_type) Does anyone know how to avoid this? I tried shrinking the volume eraser size. I also tried installing Chimera on a different computer to see if that was the problem, but it still isn't working. Thanks, Josh

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writing MRC maps
by Dougherty, Matthew T 24 Aug '10

24 Aug '10

I have an MRC map that is 800^3. I do a color zone and split the map, generating eight maps, each 800^3. The first of the split maps I throw away, the volume of interest of the other seven maps is 50^3 each. How do I save the seven maps not at 800^3, but reduce their size to 50^3? thanks, Matt

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sausage view
by lalit.deshmukh＠huskymail.uconn.edu 24 Aug '10

24 Aug '10

Hello, Is there anyway to generate a sausage view (see the attached image) by using Chimera? My apologies if I missed something/or this has been discussed before. Thanks in advance, Regards, Lalit

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Ringer: A program to detect molecular motions by systematic X-ray electron-density sampling
by Terry Lang 20 Aug '10

20 Aug '10

The Alber lab at UC Berkeley is pleased to release of the code for Ringer version 1.0 (http://ucxray.berkeley.edu/ringer.htm) which depends on Chimera. Ringer is a program to detect molecular motions by systematic X-ray electron-density sampling. The aim of Ringer is to go beyond static structural snapshots of proteins by uncovering structural ensembles in X-ray electron density. This information can reveal not only which parts of proteins are flexible and which parts are rigid, but it also can define alternate conformations that may be important for function. Alternate conformations of binding sites also may afford additional targets for drug design. The Ringer method is described in Lang et al. /Protein Sci/. 2010 Jul; 19(7):1420-31 <http://www.ncbi.nlm.nih.gov/pubmed/20499387>. An application of Ringer, determining the structural underpinnings of the side chain dynamics critical for the function of the enzyme proline isomerase, was published in Fraser JS et al. /Nature/. 2009 Dec 3;462(7273):669-73 <http://www.ncbi.nlm.nih.gov/pubmed/19956261>. Ringer is freely available to academics. -- PaulaTherese Lang Postdoctoral Scholar Alber Lab, UC Berkeley http://ucxray.berkeley.edu/ringer.htm

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Question regarding Chimera Measurements
by Shahmoradian, Sarah H 19 Aug '10

19 Aug '10

Hello, This is an urgent question and your help would be appreciated. I am trying to find a way to perform measurements in my tomogram volume file (.rec file). I tried using the "Distances" option under Tools --> Structure analysis, but this requires two "atoms." My tomogram does not depict at the atomic resolution and I would like to measure the distance between one area on my tomogram density and another area on the tomogram density. These measurements would be through a 3D section. Could you please let me know how I could do this? Furthermore, I have a question about the scale bar -- when the program generates a default scale bar, how does the program assign the default value to the scale bar size? Does it read the header info from my tomogram file? I am concerned because when I change the label name from Angstrom to nanometers, the scale bar size stays the same-- how then, would I be able to assign an accurate scale bar that would change accordingly with the alterations in scale (Angstrom to nm, etc)? Please let me know if I need to clarify further. Your assistance would be appreciated! Sincerely, Sarah Shahmoradian Molecular Physiology and Biophysics (Baylor College of Medicine) Pre-doctoral fellow, Nanobiology Interdisciplinary Graduate Training Program (Rice University)

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Positioning of water molecules in a protein
by Beale, John 19 Aug '10

19 Aug '10

Is there a way to use Chimera to determine what atoms/groups in a protein are closest to a particular water molecule? I have an x-ray structure that is solvated. I would like to determine the positions of the water molecules in the x-ray structure and compare these to the water molecule positions after molecular dynamics. Thanks! John John M. Beale, Jr., Ph.D. Professor of Medicinal Chemistry and Pharmacognosy Saint Louis College of Pharmacy 4588 Parkview Place Saint Louis, Missouri 63110 314-446-8461 Cell: 314-315-0409 FAX: 314-446-8460 jbeale(a)stlcop.edu<mailto:jbeale@stlcop.edu>

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Stereo monitors
by Jeremy Swan 18 Aug '10

18 Aug '10

Hi all, Any recommendations on stereo monitors for chimera on a pc? Thanks! -Jeremy Sent from iPhone

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