February 2021 - Chimera-users - RBVI Mailing Lists

on chimera mask
by Smith Lee 22 Feb '21

22 Feb '21

Dear All, When I use command "mask ones #0" to get the mask for #0 image and use the mask.mrc for further processing by other program, it says the mask.mrc got was not in the "cube volume" format. Will you please explain what is the "cube volume" format mrc, and is any way to convert the above mentioned 'non-cube volume" format mask.mrc to "cube volume" format mask.mrc? Best wishes, Smith

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Green bars in side view on new install
by Rochelin Dalangin 21 Feb '21

21 Feb '21

Hello, I installed Chimera 1.15 on a Windows 10 Pro laptop running i5-10300H and Intel UHD 630. When I try to open side view to clip the protein, I end up with green bars on the side view window (as shown). I've tried reinstalling to see if that fixes the issue, but it didn't work. Would you have any idea what's causing this? Thanks, Rochelin [image: image.png] -- ------------- Rochelin Dalangin Department of Chemistry 4-135 Centennial Centre for Interdisciplinary Science University of Alberta Edmonton, AB T6G 2G2

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saving several pdb files in one
by Dieter Blaas 18 Feb '21

18 Feb '21

Dear Elaine and all, I have a large number of aligned pdb files and want to mask a volume including density near all these atoms. Is there an easy way of doing so? Usually I would load map and pdb, position the pdb model accordingly, activate all atoms and use 'zone' to mask everything further away from all atoms than a given distance. But this seams to be difficult with more than 100 coordinate files, each containing about 1000 coorinates! I also tried to combine all coordinates in a single file omitting everything else but chimera tries desperately to find secondary structure elements, which is difficult with this mess.... Is there an easy way of doing so? Thanks, best, Dieter ------------------------------------------------------------------------ Dieter Blaas, Max 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, Mobile: 0043 699 1942 1659 e-mail:dieter.blaas@meduniwien.ac.at ------------------------------------------------------------------------

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Installing chimerax linux
by Francesco Pietra 18 Feb '21

18 Feb '21

Hello I would like to change to chimerax, installing it on Debian (10 Buster) Regrettably, it has become practice to refer to ubuntu when .deb packages are concerned. I would appreciate being informed which u. version, if any, is suitable for Debian 10 thanks francesco pietra

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Hide (pseudo-)bond between neighboring residues
by Konstantin Richter 18 Feb '21

18 Feb '21

Dear Chimera Community, I currently experience some trouble hiding certain bonds that Chimera automatically displays. But first things first: I want to design a figure of the active site of two very similar protein structures (models #0 and #1; let's assume they are mutants of the same molecule differing in only a few amino acid residues). I therefore display the ribbon as well as certain residues of model #0. Additionally, I align #1 on #0 and display the same residues in #1, but without the ribbon. So, the side chains of #1 should end in the ribbon of #0 (which is basically identical to ribbon #1). Since Chimera automatically displays all atoms of the residues when the respective ribbon is hidden, I also hide C,O,N of #1 residues. Now this looks fine expect for one thing. Chimera creates long (pseudo?)bonds between the CA atoms of residues that follow one another in sequence, e.g. res 64 and 65. This very long 'bond' messes up my figure, and I haven't yet figured out how to delete or hide it. I already tried the ~bond #1:64-65@CA command, but this one hides ALL bonds in residue 64 (but not the one between 64-Ca and 65-Ca) and other variations of the atom specifier. Is something wrong with my atom specification, or is this command not suitable for what I want to do? I also tried the bonddisplay command without succes, since it deletes all bonds in one residue. In the end, I want the residues of #1 to contain all atoms except for C,N,O including bonds between all atoms, but not the elongated connection between Ca atoms. best regards Konstantin Richter -- P. Konstantin Richter - M.Sc. Biochemistry Department of Structure Analysis of Biopolymers - Institute of Bioanalytical Chemistry Center for Biotechnology and Biomedicine (BBZ) - Leipzig University Deutscher Platz 5 D-04103 Leipzig Tel.: +49 341 9731316

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Writing each rotamers to individual PDB file
by Chemmama, Ilan 17 Feb '21

17 Feb '21

Dear Developers, I am trying to write a PDB for each rotamer in Chimera. I run the command: `swapaa RES :RESNUM lib Dunbrack criteria manual` I get the enumeration for each rotamers from SCRWL library. I was wondering if there was a way to write each of those rotamers into separate PDB file using a script. Some residues have large number of possible rotamers and manually selecting the rotamer and saving the PDB file is not tractable. Thank you very much ! Ilan

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fill solvent accessible channels
by Dieter Blaas 16 Feb '21

16 Feb '21

Hi, I am wondering whether chimera can fill/colour channels accessible from outside of a cryo-EM density map at a given level! If so, how? I'd like to check for size selectivity. Thanks, best, Dieter ------------------------------------------------------------------------ Dieter Blaas, Max 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, Mobile: 0043 699 1942 1659 e-mail: dieter.blaas(a)meduniwien.ac.at ------------------------------------------------------------------------

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Homology modelling with Chimera/Modeller
by StaidsonBio 16 Feb '21

16 Feb '21

Hi: I am trying to do homology modelling with Chimera/Modeler for a Fc fusion protein, which contains three domains, one is Fc, one is receptor and the 3rd is ligand. Fc has many PBD structures in PDB database and the receptor has couple of 3D structures with the ligand as well. I used the fusion protein sequence to do blast in Chimera and it gave matched sequence files to Fc domain only, no sequence files for the receptor-ligand complex, even it already has couple of solved 3D crystal structure files in PDB database. Is there any suggestion about this issue? Can I do separately, use Fc domain alone as search sequence for its template and use receptor-ligand sequences as search sequence for its template? If it is ok, there are two template files. How to make them into one template file for modelling late? Thanks very much for your suggestion. Sincerely TW Sent from Mail for Windows 10

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Cutoff for clustering
by Yasser Almeida 15 Feb '21

15 Feb '21

Hello, I have a question regarding the clustering in the MD Movie tool (MD Movie/Analysis/Cluster). What's the RMSD cutoff value to make the clustering? I don't see any mention of this in the documentation. Thanks in advance, -Yasser

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fitting open conformation (map)
by Neha Gandhi 13 Feb '21

13 Feb '21

Hi Elaine, There is a cryo-EM structure of the spike trimer in closed conformation. I have downloaded pdb file and map files for the locked conformation. I am interested in aligning or mapping map of the open conformation (fitting pdb from closed conformation pdb on the map). Could you please advise how this can be achieved? Many thanks, Neha -- Regards, Dr. Neha S. Gandhi, Vice Chancellor's Research Fellow, Queensland University of Technology, 2 George Street, Brisbane, QLD 4000 Australia LinkedIn Research Gate <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_cam…> Virus-free. www.avg.com <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_cam…> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

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Chimera-users February 2021