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showing salt bridges in pdb trajectory movie
by Albert Lyons 18 May '13

18 May '13

Hi all, I am having a problem trying to show salt bridges between selected atoms in a movie of my pdb format trajectory. I am using the following commands in the Per-Frame script, to display H-bonds between the residues but with a less strong distance criterion (to bring the distance of interaction to 6 A) and angle criterion (to make the angle 0deg and so make all angles available): select :1,6,7,10,16,18 findhbond selRestrict :1@HZ1,HZ2,HZ3 :6@2HH2,2HH1,HE,2HH1,1HH1 :7@O3P,O2P,O1P :10@HZ1,HZ2,HZ3 :16@HZ1,HZ2,HZ3 :18@2HH2,2HH1,HE,2HH1,1HH1 linewidth 2 reveal true relax true distSlop 2.97 angleSlop 145 When I apply this script I get a Chimera error saying: Error while sourcing select :1,6,7,10,16,18 findhbond selRestrict :1@HZ1,HZ2,HZ3 :6@2HH2,2HH1,HE,2HH1,1HH1 :7@O3P,O2P,O1P :10@HZ1,HZ2,HZ3 :16@HZ1,HZ2,HZ3 :18@2HH2,2HH1,HE,2HH1,1HH1 linewidth 2 reveal true relax true distSlop 2.97 angleSlop 145 ,line 1: "findhbond selRestrict :1@HZ1,HZ2,HZ3 :6@2HH2,2HH1,HE,2HH1,1HH1 :7@O3P,O2P,O1P :10@HZ1,HZ2,HZ3 :16@HZ1,HZ2,HZ3 :18@2HH2,2HH1,HE,2HH1,1HH1 linewidth 2 reveal true relax true distSlop 2.97 angleSlop 145" Non-alphanumeric character in keyword ':6@2HH2,2HH1,HE,2HH1,1HH1' I have tried tweaking it different ways but just get other error messages, I can't seem to write it in the correct format. Can anyone see a problem with this script and how I might fix it? Cheers Albie

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showing salt bridges in pdb trajectory movie
by Albert Lyons 18 May '13

18 May '13

Hi all, I am having a problem trying to show salt bridges between selected atoms in a movie of my pdb format trajectory. I am using the following commands in the Per-Frame script, to display H-bonds between the residues but with a less strong distance criterion (to bring the distance of interaction to 6 A) and angle criterion (to make the angle 0deg and so make all angles available): select :1,6,7,10,16,18 findhbond selRestrict :1@HZ1,HZ2,HZ3 :6@2HH2,2HH1,HE,2HH1,1HH1 :7@O3P,O2P,O1P :10@HZ1,HZ2,HZ3 :16@HZ1,HZ2,HZ3 :18@2HH2,2HH1,HE,2HH1,1HH1 linewidth 2 reveal true relax true distSlop 2.97 angleSlop 145 When I apply this script I get a Chimera error saying: Error while sourcing select :1,6,7,10,16,18 findhbond selRestrict :1@HZ1,HZ2,HZ3 :6@2HH2,2HH1,HE,2HH1,1HH1 :7@O3P,O2P,O1P :10@HZ1,HZ2,HZ3 :16@HZ1,HZ2,HZ3 :18@2HH2,2HH1,HE,2HH1,1HH1 linewidth 2 reveal true relax true distSlop 2.97 angleSlop 145 ,line 1: "findhbond selRestrict :1@HZ1,HZ2,HZ3 :6@2HH2,2HH1,HE,2HH1,1HH1 :7@O3P,O2P,O1P :10@HZ1,HZ2,HZ3 :16@HZ1,HZ2,HZ3 :18@2HH2,2HH1,HE,2HH1,1HH1 linewidth 2 reveal true relax true distSlop 2.97 angleSlop 145" Non-alphanumeric character in keyword ':6@2HH2,2HH1,HE,2HH1,1HH1' I have tried tweaking it different ways but just get other error messages, I can't seem to write it in the correct format. Can anyone see a problem with this script and how I might fix it? Cheers Albie

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Re: [Chimera-users] Conserved amino acids
by Rebecca Swett 17 May '13

17 May '13

Use match-> align to get a structural superposition and sequence alignment, then set your alignment type to AL2CO. Go to render by attribute and then hit the select by attribute tab. Select the range from 0-whatever your maximum is. Should be around 4 if you've got any conserved tryptophans. That will select all invariant residues. Jean-Paul Boissel <boissel(a)uni-mainz.de> wrote: >Hi, > >By homology modelling, I got putative structures for five closely related >amino acid transporters. Is there any script that will allow the quick >selection and visualisation of the invariant residues on the structures? >Thanks, > >Jean-Paul > > > > > >_______________________________________________ >Chimera-users mailing list >Chimera-users(a)cgl.ucsf.edu >http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users

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Conserved amino acids
by Jean-Paul Boissel 17 May '13

17 May '13

Hi, By homology modelling, I got putative structures for five closely related amino acid transporters. Is there any script that will allow the quick selection and visualisation of the invariant residues on the structures? Thanks, Jean-Paul

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Carbon color of 1 chain
by Markus Heller 16 May '13

16 May '13

Hello, I don't seem to be able to figure out how to color a scene by element, but with different carbon colors for different chains. I can't figure out how to get an expression like "color green, chain C C" Or something like that ... How to go about this? Thanks and Cheers Markus -- Markus Heller, Ph.D. NMR Scientist CDRD - The Centre for Drug Research and Development 2405 Wesbrook Mall, Fourth Floor | Vancouver, BC V6T 1Z3 | Main: (604) 827-1147 Direct: (604) 827-1122 | F: (604) 827-1299 | E: mheller(a)cdrd.ca<mailto:kessabar@cdrd.ca> | www.cdrd.ca

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Re: [Chimera-users] energy optimization of the modle from homology modeling
by Elaine Meng 16 May '13

16 May '13

Hello, I agree with what Tom Goddard said: "How to make a suitable homology model for docking and what force fields to use are not questions specific to Chimera, they are questions about how to do good quality science, and they depend a great deal on the details of your system. So you aren't likely to get the answers you want on this list." Instead, you have to use your scientific judgement and your knowledge of this protein, how similar it is to the template protein, etc. The procheck statistics are only one thing to consider. One reason is that they are for the whole protein, whereas you mostly care about the binding site. Another is that they focus on stereochemical quality, mainly torsion angles, but not other descriptors such as whether the protein is well packed. You could see what others have done in published papers, and/or ask on the Computational Chemistry List (see <http://ccl.net/cgi-bin/ccl/send_ccl_message>) and the Modeller discussion forum (see <http://salilab.org/modeller/discussion_forum.html>) if it is recommended to minimize homology-modeled structures before docking. In complicated structures like proteins, atoms may "feel" multiple conflicting forces, and minimization will usually relieve some strains (for example, move atoms apart if they are too close together) but increase others (for example, distort the angles of the sidechains containing those atoms). That is why the statistics from procheck got worse. It is important to realize that minimization has very little ability to fix a complicated structure with a rugged energy landscape. It is good for cleaning up small molecules, and sometimes for cleaning up a localized area (leaving the rest of the protein unchanged) where you have made some change such as manually rotating some bonds or mutating a residue. It will not predict any significant conformational change to find the global optimum. If you don't have any specific reason to minimize the structure, it might be better not to minimize it. That is only my guess, and you could probably get more expert opinions by asking your question on the other discussion lists mentioned above. If your docking doesn't take too long, you could try docking to more than conformation of the protein (more than one model). Chimera does not do molecular dynamics, although it can show MD results from other programs. However, Modeller itself does sampling to generate multiple models. Also, you could consider using Modeller to further refine parts of the model(s) from the first Modeller calculation. The Modeller scores should provide some indication of which models and refinements are better. <http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/mo…> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On May 14, 2013, at 9:39 AM, Conrad Huang wrote: > Unfortunately, that is getting well beyond my understanding of molecular mechanics. I will have to defer this to our expert when she returns. > > Conrad > > On 5/13/2013 7:56 PM, aixintiankong wrote: >> Dear, >> Thank you for your patience to answer my questions in detail. >> Before /minimizating/ the model, i use the procheck to check the >> quality of the model. the residues in most favoured regions is 95.6% and >> the disallowed regions is 0.0%, the the residues had an averaged 3D-1D >> score>0.2 is 92.02% and the errat is 90.55. >> if i use the chimera to minimizate the model after 200 steps, the >> most favoured regions is 85.5% and the disallowed regions is 0.4%, the >> the residues had an averaged 3D-1D score>0.2 is 99.2% and the errat is >> 95.968. >> if i use the chimera to minimizate the model after 250 using the >> ff99sb! force filed, the most favoured regions is 92.1% and the >> disallowed regions is 0.4%, the the residues had an averaged 3D-1D >> score>0.2 is 96.96% and the errat is 98.000. >> if i use the chimera to minimizate the model after 500ns the most >> favoured regions is 90.8% and the disallowed regions is 0.4%, the the >> residues had an averaged 3D-1D score>0.2 is 96.58% and the errat is 96.047. >> which one model should i select to make docking . >> thank you very much! >> >> At 2013-05-14 00:24:03,"Conrad Huang" <conrad(a)cgl.ucsf.edu> wrote: >>> Unfortunately, our local expert on this is on vacation and will be back >>> at the end of the week, so a more definitive answer should come then. >>> In the mean time, I'll try to answer as best as I can. >>> >>> First, Homology Modeling uses Modeller and that does a bit of >>> optimization already. If the model structure looks reasonable, further >>> energy optimization might be helpful. On the other hand, if the model >>> has extended chains because Modeller does not have appropriate templates >>> or just looks unreasonable because the model is not well packed or has >>> large dangling loops, then energy minimization probably will not help. >>> >>> Second, I do not know the answer, but have you tried using the default >>> paramters? >>> >>> Third, conjugate gradient is much much slower than steepest descent, so >>> it probably pays to use steepest descent to get near the minimum before >>> starting conjugate gradient. You can look at the reported energy values >>> reported to decide whether the minimization is proceeding as expected. >>> Chimera energy minimization is not highly optimized, so it may take a >>> while to run for a large system. If only one portion of the model is >>> "interesting", e.g., an active site, it might be faster to select just >>> the region of interest (plus a buffer around it) and only optimize that >>> part. >>> >>> Hope this helps a bit. Better answers should come later in the week. >>> >>> Conrad >>> >>> On 5/11/2013 6:50 PM, aixintiankong wrote: >>>> Dear, >>>> i am a newer use the chimea, i have some question to consult to you, >>>> please help me. >>>> Frist, after Homology modeling using the chimera modeller, should i >>>> optimizate the modle by energy optimization or Molecular dynamic >>>> simulations? The next step i will use the model to make docking. >>>> Second, i want to use chimera to minimize the structrue of my modle. >>>> i select Tools>Structure Editing>Minimize Structure to perform my >>>> work, but my modle include protein and a organic molecule NAD+, so i >>>> don't know how to select the force fileds for the minimiztion of the >>>> modle. please help me. >>>> Third, if i olny want to use the conjugate gradient to perform the >>>> minimiztion, should i only need to set the steepest descent steps to 0? >>>> in general, how many conjugate gradient s! teps and size should be ? >>>> Thank you very much!

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Error reading PubChem3D SDF Files
by Jon Fuller 15 May '13

15 May '13

I tried to read an SDF file directly downloaded from pubchem into Chimera. However, I ran into the following problem (link to example file used, and reply log below). Is this expected behaviour, or a bug? Additionally I tried to import the pubchem CID 71739 (same compound) from the fetch structure by ID tab, and got the error message: Unexpected end of file (parser state: counts) in MOL/SDF file 'FILEPATH HERE!' Many thanks in advance, Jon http://pubchem.ncbi.nlm.nih.gov/vw3d/vw3d.cgi?cmd=crtvw&reqid=2385389770715… You are now running Chimera version 1.8 (build 38642). Your previous version was 1.5 (build 32133). Check the release notes for new features and other info. (To access the release notes, use the Help menu to bring up the User's Guide. Then click the 'Documentation index' link and you will then see a link for the release notes.) Error while processing CID_71739_1183b00000003_conf.sdf: Non-numeric charge (1 -0.36) in PUBCHEM_MMFF94_PARTIAL_CHARGES data Error reading CID_71739_1183b00000003_conf.sdf: Non-numeric charge (1 -0.36) in PUBCHEM_MMFF94_PARTIAL_CHARGES data Error reading CID_3672_e5800000001_conf.sdf: Non-numeric charge (1 -0.65) in PUBCHEM_MMFF94_PARTIAL_CHARGES data Error reading CID_71739_1183b00000003_conf.sdf: Non-numeric charge (1 -0.36) in PUBCHEM_MMFF94_PARTIAL_CHARGES data

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energy optimization of the modle from homology modeling
by aixintiankong 15 May '13

15 May '13

Dear, i am a newer use the chimea, i have some question to consult to you, please help me. Frist, after Homology modeling using the chimera modeller, should i optimizate the modle by energy optimization or Molecular dynamic simulations? The next step i will use the model to make docking. Second, i want to use chimera to minimize the structrue of my modle. i select Tools>Structure Editing>Minimize Structure to perform my work, but my modle include protein and a organic molecule NAD+, so i don't know how to select the force fileds for the minimiztion of the modle. please help me. Third, if i olny want to use the conjugate gradient to perform the minimiztion, should i only need to set the steepest descent steps to 0? in general, how many conjugate gradient steps and size should be ? Thank you very much!

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desmond in chimera
by lecan 15 May '13

15 May '13

Hi to everybody. Can the newest version of Chimera use the .cms files from desmond by schrodinger to analyse trajectories and make movies? Regrads, Luis L.

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surface
by Gesa Volkers 14 May '13

14 May '13

Hi chimera users/developers, I have a problem with a surface calculation from one monomer of a structure that I want to show. As you can see in this image http://imageshack.us/photo/my-images/801/testss.png/ it looks like the surface calculation failed (?) because the surface is missing in the middle (note the chewed up structure of the surface). Most of the surface is smooth but for whatever reason not this part of the structure. I have played around with probeRadius, vertex density and zone and they all increase quality but do not add the missing surface part (I'm not even sure if zone is applicable to surfaces at all or only to electron density maps). Any suggestions which parameter I am missing? Thanks for suggestions, Gesa

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