- Chimera-users - RBVI Mailing Lists

clipping related models identically
by Eric Pettersen 06 Feb '08

06 Feb '08

Raven Huang asks (paraphrased): > I have four related structures that I want to show in cutaway view, > with the cut being in the same place in all the structures. How > can I do that? The technique varies depending on whether you are clipping using the global clip planes (i.e. the ones shown in the Side View), or with per-model clip planes (from the Per-Model Clipping tool). Both techniques share the same setup step though: open all your models and get the parts you care about superimposed. If the starting coordinates are already "in the same reference frame" then you don't have to do anything but open the models. Otherwise you will have to superimpose them either with the MatchMaker tool or the "match" command. There is a discussion of using those here: http://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/tutorials/ images.html#matching To view just one of the structures at a time, use the Model Panel (Favorites->Model Panel) and use the buttons in the Shown column (or the Show Only button in the button list) to show one structure/ surface. Now for adjusting the clip plane... Global clipping: open the Side View and adjust the near clip plane until it is cutting where you want it to. Per-model clipping: use the Per-Model Clipping tool to adjust the clip plane of the visible model until it is cutting where you want it to. Then choose one of the other models you want to cut from Per- Model Clipping's "Model:" menu. Enable clipping and click the "Align plane" button once you have chosen the original model in the menu next to the button. The model clip planes will now be aligned. Once the models are all clipped, you can either show then individually (the Model Panel again) and save separate images, or move them apart using the "move" command and save one combined image. --Eric Eric Pettersen UCSF Computer Graphics Lab http://www.cgl.ucsf.edu

1 0

Planes feature in the Volume Viewer
by William Jeffrey Triffo 05 Feb '08

05 Feb '08

hi, when using the Planes tool in Volume Viewer, are the planes numbered from 0 or 1? I loaded a contour using the IMOD import, where I had drawn the contour on slice 12 of a volume; however, it appears that the plane that transects the contour in Chimera is '11' when using the Planes tool. I tried to test the enumeration by exceeding bounds (150 slices are in the volume, so was expecting an error for an entry of '150' if it was enumerated from zero), but it appears that slice indices outside the range of the loaded volume just default to the limit in either direction (typing in '200' just sets it to the highest-enumerated slice). -- ------------------------------------------------------------- Jeff Triffo Auer Group, Donner Lab, Lawrence Berkeley National Laboratory Raphael Group, Bioengineering Department, Rice University Medical Scientist Training Program (MSTP), Baylor College of Medicine phone (Berkeley): 510-486-7940 fax (Berkeley): 510-486-6488

2 1

Contact/clash detection for HETATMs
by Jonathan Magasin 05 Feb '08

05 Feb '08

Hello, I'm trying to use the clashes/contacts tool to explore valid phi/psi angles for L- and D-Ala (as part of a homework assignment; developing a Ramachandran plot for each). The tool worked great for L-Ala but does not report any contacts for D-Ala. (For each, I've snipped just the relevant sections out of a larger PDB. I'm using default params for collision detection, with detection calculated for any movement.) The difference in the PDB's for L-Ala and D-Ala is that the latter are in HETATM records. I did include the CONNECT info (to explicitly tell Chimera how HETATMs bond) but that did not help. Perhaps there's something else I must include, or some modification I can make to the HETATMS (element labeling?) so that collision detection will work as with peptides? Or is this a known limitation? (Is there a list of known limitations? I'm a new user.) I'm not Note that the distance tool works for D-Ala. If I can get collision detection to work, it take much less time. Thanks in advance. -Jonathan

2 1

Aligning two residues same name
by Elaine Meng 05 Feb '08

05 Feb '08

> Changing residue name works. Deleted membrane, saved pdb without > membrane. > Loaded the two models. Command line: match :XXX :YYY Hi Francesco, You can still use the name without changing it, for example open 4hhb open 4cpp preset apply interactive 1 match #1:hem #0:hem.a ~ribbon This matches the single heme residue of 4cpp (#1) to the chain A heme of 4hbb (#0 - it has four heme residues, in chains A-D). The protein parts are totally different but I just used this as an example because they both have heme. It takes a little time, but I recommend learning about the command- line specification language because it is used in so many commands, and can be very powerful yet flexible. http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/ frameatom_spec.html Or, for some quick hints see the examples on the second page of the "Quick Reference": http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/quickref.pdf Elaine ----- Elaine C. Meng, Ph.D. meng(a)cgl.ucsf.edu UCSF Computer Graphics Lab and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html

1 0

Re: [Chimera-users] [Dock-fans] How to get the charged mol for the ligand
by cpsosa＠comcast.net 04 Feb '08

04 Feb '08

Thanks. We tried that but after the hydrogens were added. We saved it and "vi" the mol2 file. I'll try this. -- Carlos P. Sosa -------------- Original message ---------------------- From: Eric Pettersen <pett(a)cgl.ucsf.edu> > I forgot, there's actually a fourth thing you can do: change the > atom type directly. Select the oxygen atom and open the command line > (Favorites->Command Line) and type: > > setattr a idatmType O3 sel > > which will set the selected atom's "idatmType" attribute to sp3 > oxygen ("O3"). > > Do this before hydrogens are added. > > --Eric > > Eric Pettersen > UCSF Computer Graphics Lab > http://www.cgl.ucsf.edu > > > On Feb 3, 2008, at 1:27 PM, Eric Pettersen wrote: > > > Hi Carlos, > > There are basically three things you can do: > > > > 1) Download the latest daily build and try that. I have been > > working hard on atom typing for ring systems recently (and am still > > working on it) and there's a pretty good chance that it will type > > (and therefore protonate) the phenyl oxygen correctly now. You > > get a daily build by going to the Chimera home page > > (www.cgl.ucsf.edu/chimera) and following the "Daily Builds" link. > > > > 2) Directly edit the structure (after adding hydrogens but before > > adding charges). Control-double-click the oxygen and select > > "Modify Atom" from the pop-up menu. In the resulting dialog change > > the element type to O, the geometry to tetrahedral, and the number > > of bonds to 2. You should also probably change the atom name field > > to be the same as what the atom's name is. Then click the Change > > button and the hydrogen will be added. > > > > 3) Before doing any processing, change the bond length. Control > > double-click on the C-O bond and choose "Set Bond Length" from the > > pop-up menu. Type in a bond length appropriate for a C-O single > > bond and then run the rest of your processing. > > > > --Eric > > > > Eric Pettersen > > UCSF Computer Graphics Lab > > > > On Feb 2, 2008, at 5:19 PM, cpsosa(a)comcast.net wrote: > > > >> > >> Hello, > >> > >> We have the opposite problem, our PDB has one oxygen that is part > >> of a phenyl group and after using addH in Chimera, hydrogen does > >> not get added to that oxygen. Is there a way to add hydrogen to a > >> single atom? using Chimera. For Chimera to add a hydrogen to > >> that O... perhaps making the C-O bond larger. > >> > >> Any suggestions? > >> > >> Thanks, > >> > >> -- > >> Carlos P. Sosa > >> > >> -------------- Original message ---------------------- > >> From: Eric Pettersen <pett(a)cgl.ucsf.edu> > >>> I assume this is IMZ from 1rv1? Chimera is adding a proton to > >>> the N3 > >>> nitrogen that it shouldn't. After adding hydrogens and before > >>> saying > >>> OK to the charge calculation, type this command to Chimera's command > >>> line to delete the extra hydrogen: > >>> > >>> del :IMZ@h3 > >>> > >>> --Eric > >>> > >>> Eric Pettersen > >>> UCSF Computer Graphics Lab > >>> http://www.cgl.ucsf.edu > >>> > >>> > >>>> I could not get the charges for my molecule (ligand in x-crystal > >>>> structure). how to do that? > >>>> I am getting the following error message. > >>>> I am using chimera to do these funtions. > >>>> > >>>> Running ANTECHAMBER command: C:\Program Files\Chimera\bin > >>>> \antechamber\exe\antechamber -i c:\docume~1\thomas\locals~1\temp > >>>> \tmpkzw4il\ante.in.mol2 -fi mol2 -o c:\docume~1\thomas\locals~1 > >>>> \temp > >>>> \tmpkzw4il\ante.out.mol2 -fo mol2 -c bcc -nc 1 -j 5 -s 2 > >>>> (IMZ) > >>>> (IMZ) Running: "C:\Program Files\Chimera\bin\antechamber"\exe > >>>> \bondtype -i ANTECHAMBER_BOND_TYPE.AC0 -o > >>>> ANTECHAMBER_BOND_TYPE.AC - > >>>> f ac -j part > >>>> (IMZ) > >>>> (IMZ) Running: "C:\Program Files\Chimera\bin\antechamber"\exe > >>>> \atomtype -i ANTECHAMBER_AC.AC0 -o ANTECHAMBER_AC.AC -p gaff > >>>> (IMZ) Total number of electrons: 351; net charge: 1 > >>>> (IMZ) INFO: Number of electrons is odd: 351 > >>>> (IMZ) Please check the total charge (-nc flag) and spin > >>>> multiplicity (-m flag) > >>>> Failure running ANTECHAMBER for residue IMZ > >>>> > >>>> > >>>> Thomas > >>> > >>> > >> > >> > >> > >> From: Eric Pettersen <pett(a)cgl.ucsf.edu> > >> Date: January 31, 2008 12:54:24 PM PST > >> To: dock-fans(a)docking.org > >> Subject: Re: [Dock-fans] How to get the charged mol for the ligand > >> > >> > >> I assume this is IMZ from 1rv1? Chimera is adding a proton to the > >> N3 nitrogen that it shouldn't. After adding hydrogens and before > >> saying OK to the charge calculation, type this command to > >> Chimera's command line to delete the extra hydrogen: > >> > >> del :IMZ@h3 > >> > >> --Eric > >> > >> Eric Pettersen > >> UCSF Computer Graphics Lab > >> http://www.cgl.ucsf.edu > >> > >> > >>> I could not get the charges for my molecule (ligand in x-crystal > >>> structure). how to do that? > >>> I am getting the following error message. > >>> I am using chimera to do these funtions. > >>> > >>> Running ANTECHAMBER command: C:\Program Files\Chimera\bin > >>> \antechamber\exe\antechamber -i c:\docume~1\thomas\locals~1\temp > >>> \tmpkzw4il\ante.in.mol2 -fi mol2 -o c:\docume~1\thomas\locals~1 > >>> \temp\tmpkzw4il\ante.out.mol2 -fo mol2 -c bcc -nc 1 -j 5 -s 2 > >>> (IMZ) > >>> (IMZ) Running: "C:\Program Files\Chimera\bin\antechamber"\exe > >>> \bondtype -i ANTECHAMBER_BOND_TYPE.AC0 -o > >>> ANTECHAMBER_BOND_TYPE.AC -f ac -j part > >>> (IMZ) > >>> (IMZ) Running: "C:\Program Files\Chimera\bin\antechamber"\exe > >>> \atomtype -i ANTECHAMBER_AC.AC0 -o ANTECHAMBER_AC.AC -p gaff > >>> (IMZ) Total number of electrons: 351; net charge: 1 > >>> (IMZ) INFO: Number of electrons is odd: 351 > >>> (IMZ) Please check the total charge (-nc flag) and spin > >>> multiplicity (-m flag) > >>> Failure running ANTECHAMBER for residue IMZ > >>> > >>> > >>> Thomas > >> > >> > >> _______________________________________________ > >> Dock-fans mailing list > >> Dock-fans(a)docking.org > >> http://blur.compbio.ucsf.edu/mailman/listinfo/dock-fans > >> > >> > > > > _______________________________________________ > > Chimera-users mailing list > > Chimera-users(a)cgl.ucsf.edu > > http://www.cgl.ucsf.edu/mailman/listinfo/chimera-users >

1 0

Fwd: Loading prmtop/mdcrd with partial workout
by Francesco Pietra 04 Feb '08

04 Feb '08

What I asked below has no sense. Deleting residues does not freed memory. Of course, because those residues can be resumed. francesco --- Francesco Pietra <chiendarret(a)yahoo.com> wrote: > Date: Fri, 1 Feb 2008 12:49:22 -0800 (PST) > From: Francesco Pietra <chiendarret(a)yahoo.com> > Subject: Loading prmtop/mdcrd with partial workout > To: chimera <chimera-users(a)cgl.ucsf.edu> > > I am experiencing difficulties with Amber ptraj in removing solvent/lipid/box > (i.e., unexpected problems of prmtop fitting after that, though I used a > prmtop > before creating solvent/lipid/box). > > Otherwise, I have memory problems with Chimera in loading such an extensive > MD > (many ns, in various coordinate files) with all the burden of > solvent/lipid/box. > > My question: is that feasible with Chimera to load a coordinate file, remove > solvent and lipid, load a second coordinate file, remove solvent and lipid, > and > so on for all coordinate files? > > Thanks > > francesco pietra > > > > ____________________________________________________________________________________ > Be a better friend, newshound, and > know-it-all with Yahoo! Mobile. Try it now. > http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ > > ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

2 1

Re: [Chimera-users] [Dock-fans] How to get the charged mol for the ligand
by Eric Pettersen 04 Feb '08

04 Feb '08

Hi Carlos, There are basically three things you can do: 1) Download the latest daily build and try that. I have been working hard on atom typing for ring systems recently (and am still working on it) and there's a pretty good chance that it will type (and therefore protonate) the phenyl oxygen correctly now. You get a daily build by going to the Chimera home page (www.cgl.ucsf.edu/ chimera) and following the "Daily Builds" link. 2) Directly edit the structure (after adding hydrogens but before adding charges). Control-double-click the oxygen and select "Modify Atom" from the pop-up menu. In the resulting dialog change the element type to O, the geometry to tetrahedral, and the number of bonds to 2. You should also probably change the atom name field to be the same as what the atom's name is. Then click the Change button and the hydrogen will be added. 3) Before doing any processing, change the bond length. Control double-click on the C-O bond and choose "Set Bond Length" from the pop-up menu. Type in a bond length appropriate for a C-O single bond and then run the rest of your processing. --Eric Eric Pettersen UCSF Computer Graphics Lab On Feb 2, 2008, at 5:19 PM, cpsosa(a)comcast.net wrote: > > Hello, > > We have the opposite problem, our PDB has one oxygen that is part > of a phenyl group and after using addH in Chimera, hydrogen does > not get added to that oxygen. Is there a way to add hydrogen to a > single atom? using Chimera. For Chimera to add a hydrogen to that > O... perhaps making the C-O bond larger. > > Any suggestions? > > Thanks, > > -- > Carlos P. Sosa > > -------------- Original message ---------------------- > From: Eric Pettersen <pett(a)cgl.ucsf.edu> >> I assume this is IMZ from 1rv1? Chimera is adding a proton to the N3 >> nitrogen that it shouldn't. After adding hydrogens and before saying >> OK to the charge calculation, type this command to Chimera's command >> line to delete the extra hydrogen: >> >> del :IMZ@h3 >> >> --Eric >> >> Eric Pettersen >> UCSF Computer Graphics Lab >> http://www.cgl.ucsf.edu >> >> >>> I could not get the charges for my molecule (ligand in x-crystal >>> structure). how to do that? >>> I am getting the following error message. >>> I am using chimera to do these funtions. >>> >>> Running ANTECHAMBER command: C:\Program Files\Chimera\bin >>> \antechamber\exe\antechamber -i c:\docume~1\thomas\locals~1\temp >>> \tmpkzw4il\ante.in.mol2 -fi mol2 -o c:\docume~1\thomas\locals~1\temp >>> \tmpkzw4il\ante.out.mol2 -fo mol2 -c bcc -nc 1 -j 5 -s 2 >>> (IMZ) >>> (IMZ) Running: "C:\Program Files\Chimera\bin\antechamber"\exe >>> \bondtype -i ANTECHAMBER_BOND_TYPE.AC0 -o ANTECHAMBER_BOND_TYPE.AC - >>> f ac -j part >>> (IMZ) >>> (IMZ) Running: "C:\Program Files\Chimera\bin\antechamber"\exe >>> \atomtype -i ANTECHAMBER_AC.AC0 -o ANTECHAMBER_AC.AC -p gaff >>> (IMZ) Total number of electrons: 351; net charge: 1 >>> (IMZ) INFO: Number of electrons is odd: 351 >>> (IMZ) Please check the total charge (-nc flag) and spin >>> multiplicity (-m flag) >>> Failure running ANTECHAMBER for residue IMZ >>> >>> >>> Thomas >> >> > > > > From: Eric Pettersen <pett(a)cgl.ucsf.edu> > Date: January 31, 2008 12:54:24 PM PST > To: dock-fans(a)docking.org > Subject: Re: [Dock-fans] How to get the charged mol for the ligand > > > I assume this is IMZ from 1rv1? Chimera is adding a proton to the > N3 nitrogen that it shouldn't. After adding hydrogens and before > saying OK to the charge calculation, type this command to Chimera's > command line to delete the extra hydrogen: > > del :IMZ@h3 > > --Eric > > Eric Pettersen > UCSF Computer Graphics Lab > http://www.cgl.ucsf.edu > > >> I could not get the charges for my molecule (ligand in x-crystal >> structure). how to do that? >> I am getting the following error message. >> I am using chimera to do these funtions. >> >> Running ANTECHAMBER command: C:\Program Files\Chimera\bin >> \antechamber\exe\antechamber -i c:\docume~1\thomas\locals~1\temp >> \tmpkzw4il\ante.in.mol2 -fi mol2 -o c:\docume~1\thomas\locals~1 >> \temp\tmpkzw4il\ante.out.mol2 -fo mol2 -c bcc -nc 1 -j 5 -s 2 >> (IMZ) >> (IMZ) Running: "C:\Program Files\Chimera\bin\antechamber"\exe >> \bondtype -i ANTECHAMBER_BOND_TYPE.AC0 -o ANTECHAMBER_BOND_TYPE.AC >> -f ac -j part >> (IMZ) >> (IMZ) Running: "C:\Program Files\Chimera\bin\antechamber"\exe >> \atomtype -i ANTECHAMBER_AC.AC0 -o ANTECHAMBER_AC.AC -p gaff >> (IMZ) Total number of electrons: 351; net charge: 1 >> (IMZ) INFO: Number of electrons is odd: 351 >> (IMZ) Please check the total charge (-nc flag) and spin >> multiplicity (-m flag) >> Failure running ANTECHAMBER for residue IMZ >> >> >> Thomas > > > _______________________________________________ > Dock-fans mailing list > Dock-fans(a)docking.org > http://blur.compbio.ucsf.edu/mailman/listinfo/dock-fans > >

1 1

Aligning two residues same name
by Francesco Pietra 04 Feb '08

04 Feb '08

Task: compare/align a single-residue molecule before docking (naked molecule, mol2 or pdb file) with same residue as ligand in a protein after docking/MD (pdb file of a snapshot for complex embedded in a bilayer membrane). Should I change the residue name in one of the two models? Same name poses to me problems. Or there is a direct way? Thanks francesco pietra ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

2 1

Fwd: Aligning two residues same name
by Francesco Pietra 04 Feb '08

04 Feb '08

Changing residue name works. Deleted membrane, saved pdb without membrane. Loaded the two models. Command line: match :XXX :YYY How to put the difference in quantitative terms (rmsd)? Thanks francesco --- Francesco Pietra <chiendarret(a)yahoo.com> wrote: > Date: Mon, 4 Feb 2008 06:59:25 -0800 (PST) > From: Francesco Pietra <chiendarret(a)yahoo.com> > Subject: Aligning two residues same name > To: chimera <chimera-users(a)cgl.ucsf.edu> > > Task: compare/align a single-residue molecule before docking (naked molecule, > mol2 or pdb file) with same residue as ligand in a protein after docking/MD > (pdb file of a snapshot for complex embedded in a bilayer membrane). Should I > change the residue name in one of the two models? Same name poses to me > problems. Or there is a direct way? > Thanks > francesco pietra > > > > ____________________________________________________________________________________ > Be a better friend, newshound, and > know-it-all with Yahoo! Mobile. Try it now. > http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ > > ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

2 1

Permission to use Chimera created image
by Seymour Yang 01 Feb '08

01 Feb '08

Hi, I wish to obtain permission to use one or two of the virus images shown on your Chimera image gallery (Semliki forest Virus and Sindbis Virus). We are writing a feature article about 3D molecular imaging and would like to include some Chimera images. May I ask whom to contact regarding permission and obtaining higher resolution files? Hope you can help. Seymour Seymour Yang Producer - Science Feature Stories Email: seymour(a)sciencephoto.com Website: www.sciencephoto.com Blog:http://sciencephoto.blogspot.com/

3 2

Loading prmtop/mdcrd with partial workout
by Francesco Pietra 01 Feb '08

01 Feb '08

I am experiencing difficulties with Amber ptraj in removing solvent/lipid/box (i.e., unexpected problems of prmtop fitting after that, though I used a prmtop before creating solvent/lipid/box). Otherwise, I have memory problems with Chimera in loading such an extensive MD (many ns, in various coordinate files) with all the burden of solvent/lipid/box. My question: is that feasible with Chimera to load a coordinate file, remove solvent and lipid, load a second coordinate file, remove solvent and lipid, and so on for all coordinate files? Thanks francesco pietra ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

1 0

screening
by snoze pa 01 Feb '08

01 Feb '08

In continuation to my previous question, Is it possible to use chimera in virtual screening?

2 1

graphics card question (survey?)
by William Jeffrey Triffo 31 Jan '08

31 Jan '08

hello, anyone out there using a Radeon HD 2600 XT or GeForce 8800 GT? Just wanted to know if there are any driver issues out there that are known - these are the two 'lower-end' options on the current Mac Pro line, and I am evaluating that as a potential purchase (so technically, my question may only be relevant if you are also using a Mac machine). likewise, if you have a current-generation Mac (Tiger/10.4 or Leopard/10.5) and have bought a third-party card that you have had success with, I am all ears. best, -Jeff -- ------------------------------------------------------------- Jeff Triffo Auer Group, Donner Lab, Lawrence Berkeley National Laboratory Raphael Group, Bioengineering Department, Rice University Medical Scientist Training Program (MSTP), Baylor College of Medicine phone (Berkeley): 510-486-7940 fax (Berkeley): 510-486-6488

1 0

fourier transforms
by Matt Shawkey 31 Jan '08

31 Jan '08

Hi, I'm doing fourier transforms of 3d volumes and noticed that they are computed in Chimera using only a small portion of the actual data available (e.g. 128 ^3 pixels rather than the 512^3 pixels in the volume). Is there a way to do a fourier transform using all of the available data? THanks, Matt

2 1

Surface color
by James Fethiere 30 Jan '08

30 Jan '08

Hi, I'm using the volume path tracer and color zone to highlight regions of a map. I would like to display a model within this region but it is not visible when I color the region with color zone. How can I make this zone transparent but still a different color that the rest of the map? Thanks James

2 1

Re: [Chimera-users] mac pro theoretical question
by Tom Goddard 29 Jan '08

29 Jan '08

Hi Jeff, I don't know much about any of the current Apple graphics cards (Radeon HD 2600 XT 256Mb, Nvidia GeForce 8800 GT 512Mb, Nvidia Quadro FX 5600 1.5Gb). My first concern would be whether bugs in the drivers for these cards are going to cause trouble in Chimera. We have a web page that lists problems with graphics drivers observed using Chimera: http://www.cgl.ucsf.edu/chimera/graphics/graphicsbugs.html#cards There was a recently reported problem (squashed atom spheres) with GeForce 8800 GTX (not GT) on Windows. The Apple driver may be much different. The Quadro FX 4500 which was Apple's high-end offering before the 5600 crashed with solid volume rendering. Don't know if the current 5600 would have the same problem -- but there is a fair chance it does. Chimera uses many different OpenGL calls and I'd guess 1 in 10 drivers exhibit bugs of varying severity when using Chimera. Some of Chimera performance is related to graphics card speed and memory, and some is related to CPU speed and memory. When the displayed models rotate slowly that is the graphics card except if you are using transparent volume surfaces or meshes which are sorted by depth on the CPU for every new view angle. Everything else is the CPU, main memory, memory cache performance, and hard-drive speed. Solid style volume rendering makes a lot of textures which usually will be stored in graphics card memory. More graphics card memory could make larger volume rotate faster because they fit on the card. 256^3 volumes (16 million voxels, 4 bytes per voxel) typically rotate at 10 frames per second with graphics memory sizes 128 Mb and up. Textures have to have power of 2 sizes so just knowing that can get you better performance if you trim your 550x550x100 region to 512x512x100 you'll get a factor of 4 speed-up. I don't know if a single application using one display can use more than one graphics card in Apple's multicard options. Chimera has no special code to do that. For large volume data, hard-drive speed, main memory size, and CPU speed are likely to be noticable factors in Chimera performance, each of about equal importance to graphics card speed. Tom > hi Tom, > > if you were considering a Mac Pro at some point in the future, what > graphics card would you pick when thinking of chimera (if you don't > mind peeking at some point at the list at > http://store.apple.com/1-800-MY-APPLE/WebObjects/AppleStore.woa/9354001/wo/… > > > are rendering bottlenecks in chimera largely a processor-limited thing > (and thus one of the 'lower end' cards listed would be fine), or > something that benefits dramatically from spending $2000 on a graphics > card (I am not in that kind of market, just wondering what kind of > decision you would make if evaluating that platform) > > best, > > -Jeff > > >

1 0

average vs ensemble
by Rachel Scherer 29 Jan '08

29 Jan '08

Given that chimera doesn't calculate average NMR structures, this query may be outside the groups interests, but can anyone suggest what the appropriate protocol is when making aa-substitutions into an NMR structure: should an "average" be calculated (by averaging the atom coordinates across all the models in a PDB file that predates inclusion of the average into the database entry) or, should one use a representative from a cluster generated with "ensemble cluster" be chosen? Or an average of the representatives of the clusters? Or, the cluster representative that best matches the calculated average? -- Rachel Scherer rachel(a)bio.umass.edu Biology Department (413)545-2825 vox UMASS Amherst (413)545-3243 fax

2 1

coordinates
by hsosa＠aecom.yu.edu 25 Jan '08

25 Jan '08

Hi, I am trying to rotate a molecule around a 3D density map. I had already saved the coordinates of the molecule relative to the map. However if I rotate the pdb file (creating a new pdb file with the rotated molecule) by rotating the coordinates around the origin (0,0,0) the new molecule is rotated around a a center that does not coincide with the center of the map. So I am confused about what are the relative positions of the origin for the map and pdb file. If I have an atom with pdb coordinates 0,0,0 should this atom appear at the center of the density map ?. Thanks Hernando -- ----------------------------------- Hernando Sosa Dept. of Physiology and Biophysics Albert Einstein College of Medicine 1300 Morris Park Av. Bronx NY 10461 phone (718) 430-3456 FAX (718) 430-8819 email hsosa(a)aecom.yu.edu -----------------------------------

2 4

Re: [Chimera-users] Save a transformed density map
by Thomas Goddard 24 Jan '08

24 Jan '08

Hi Keren, Chimera has a resampling capability for extracting regions of a map that aren't aligned with the axes. It doesn't work well in the case you want. So I've made a Chimera command that will do what you want. If your the map you wish to save in the new orientation has id number 0 (listed next to the name of the map in volume dialog), and the map you fit into has id 1 you would use the command: vop #0 resample onGrid #1 The vop stands for "volume operation". (Use menu Favorites / Command Line to type commands.) This will create the new map which will appear in the volume dialog and can be saved with the volume dialog File / Save map as... (or using a command like "volume #2 save /tmp/newmap.mrc"). The vop command with the resample operation will be in tonight's builds of Chimera (assuming they succeed). http://www.cgl.ucsf.edu/chimera/alpha-downloads.html Tom Keren Lasker wrote: > hey Tom, > > I need to save the transformed map for other calculations. Is there a > resampling option in chimera? if not I guess that I can use the output > transformation matrix generated by fit map2map - right? > > thanks, > Keren. > On Jan 24, 2008, at 3:27 PM, Thomas Goddard wrote: > >> Hi Keren, >> >> You can save the Chimera session to preserve the orientation of one >> map fit into another. >> >> If you want to write a new map so that when it is loaded in Chimera >> and other software it will be at the correct place in the map it was >> fit into that is harder. The problem is that none of the map file >> formats provide for a positioning transformation in the header. So it >> would be necessary to resample the map that you fit on the grid of the >> map you fit into. Resampling interpolates data values and can degrade >> map quality. Do you want to do that? >> >> Tom >

2 1

volume visualization
by Enrico Malito 24 Jan '08

24 Jan '08

Hello, I am trying to visualize a map as Volume (ccp4 format map calculated with VOIDOO in NEWZD then converted with MAPMAN) and somehow the map in chimera results shifted with respect to the corresponding pdb model (in a completely different place). If I open same pdb and map file in other visualization programs they are actual in the right position (map into the cavity of the enzyme). I'm opening the map from the Volume Viewer-->File-->Open map Am I doing something wrong? Thanks, EM -- Enrico Malito Ben-May Department for Cancer Research Center for Integrative Science, W423J The University of Chicago, 929 E. 57th Street, Chicago, IL, 60637 Tel: 773-702-4608 Fax: 773-702-6260 http://home.uchicago.edu/~emalito

2 2

Save a transformed density map
by Keren Lasker 24 Jan '08

24 Jan '08

hello, How can I save a transformed map after using the fit map2map option? The "save map" option saves it in its original transformation. thank you, Keren.

2 1

Chimera batch surface exporter
by Trent Grover 24 Jan '08

24 Jan '08

Hi Everyone, I'm pretty new to Chimera, but I'm working on an animation project that requires quite a few proteins and molecules. To speed up the process, I'd like to create a batch converter/exporter script to do the following: Open a PDB file Generate a multiscale model at a specified resolution Export the model out as a VRML or OBJ file I think I can do this using a Chimera command file, but I was hoping someone could point me in the right direction for some of the relevant command line syntax. Is it possible to control the multiscale model tool via command line (I know I can launch the dialog, but can I change the parameters and execute)? Is there a reference somewhere for the command line parameters for the multiscale models tool? What is the command line export command? Where can I find an OBJ exporter (there are references to it in the mailing list archive)? Any help would be greatly appreciated. Thanks, Trent BTW - I have a suggestion for improvement of Chimera. Add a command history window (or modify the existing one) that echoes out the command line text that is equivalent to any command executed via the Chimera user interface. Maya has this functionality and it is wonderful for anyone who is trying to figure out how to script a process that they know how to execute via the various menus.

2 1

Re: [Chimera-users] Surface representation
by Elaine Meng 24 Jan '08

24 Jan '08

> Hi, > I would like to know if there is a way to build a surface > representation from a pdb file of a dummy atom saxs model in > chimera. The file consist only of CA atoms. I could simulate this > by increasing the vdw radius but the model becomes way to big. > Thanks > James Hi James, You can use Multiscale Models to make a contour surface that encloses the "atoms." The tricky part may be adjusting the contour surface parameters to get the desired smoothness and enclosed total volume. At least in my tests, Chimera did not like the columns in your file after the B-factor column, so I made a version with those removed and opened it with "File... Open" before proceeding. I will send you that file in a separate message. (1) for purposes of comparison to the surface, I displayed the atoms as spheres with the radius 3.75 (this value was given in comments in the file) using the following commands: setattr a radius 3.75 rep sphere You can show the command line with Favorites... Command Line. (2) started Multiscale Models (under Tools... Higher-Order Structure), clicked the "Make models" button near the bottom. This generates the contour surface but hides the spheres. To also show the spheres, Ctrl-click on the surface to select it, and then in the "Style" line of the dialog, choose "Show also.. Spheres". To see spheres inside the surface, make it transparent; set Transparency to some fraction, say 0.3. (3) Then you can fiddle with the contour surface parameters in the Multiscale Models dialog. Many are hidden but can be shown by checking the box next to "..." I got a fairly decent enclosure of the spheres with all default parameters except setting the "Threshold atom density" for "CA only" to 0.0006 instead of the default 0.002. You could also fiddle with the smoothing parameters and resolution if that is not good enough. If you have some idea of what total volume the surface should enclose, that can be evaluated with Measure Volume and Area (under Tools... Volume Data). I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. meng(a)cgl.ucsf.edu UCSF Computer Graphics Lab and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html

3 3

Re: [Chimera-users] Chimera-users Digest, Vol 57, Issue 24
by Jonathan Hilmer 22 Jan '08

22 Jan '08

POV-Ray also works extremely well as a distributed job. This site has some basic discussion of some of the distributed POV options: http://columbiegg.com/httpov/?p=why Jonathan > Today's Topics: > > 1. (no subject) (jean-francois menetret) > 2. Re: Flip handedness of map (Tom Goddard) > 3. VRML alpha vs 1-alpha (Nils Becker) > 4. Re: VRML alpha vs 1-alpha (Greg Couch) > > > ------------------------------ > > Message: 4 > Date: Tue, 22 Jan 2008 10:37:54 -0800 (PST) > From: Greg Couch <gregc(a)cgl.ucsf.edu> > Subject: Re: [Chimera-users] VRML alpha vs 1-alpha > To: Nils Becker <nils.becker(a)ens-lyon.fr> > Cc: chimera-users(a)cgl.ucsf.edu > Message-ID: <Pine.OSF.4.63.0801220934340.1761700(a)guanine.cgl.ucsf.edu> > Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed > > On Tue, 22 Jan 2008, Nils Becker wrote: > > > Hi, > > > > I found information on the web site that VRML models use > > 1-alpha blending for transparency, and that that looks ugly. > > I agree. > > > > Now I have externally generated VRML files including transparency. > > > > Is there a way to get nice (normal) transparency rendering of these > > models in chimera? > > > > e.g. editing the vrml files, converting them to another format or some > > option inside chimera? > > > > Thanks for any help, cheers, Nils > > The VRML transparency is 1-alpha, because alpha is an opacity value. So > that is just an alternative way of saying that same thing, and is not the > reason it is worse. > > The reason VRML transparency is worse is that there is no sorting within > the VRML shapes, so the blending of transparent objects has to be > drawing-order independent, so VRML uses additive blending. > > The simpliest solution would be to live with chimera's current depiction > and use the Save Image dialog to generate a ray-traced version. The > ray-traced version will be much nicer (and take a lot longer to compute, > try using the POV-Ray 3.7 beta on a multi-core computer to speed things > up). > > The other solution, is to write some Python code and use the _surface > module's Surface_Model and Surface_Group classes. That is, convert each > VRML object into a triangulated surface, a Surface_Group, and put all of > the Surface_Groups into one Surface_Model. All surfaces within one > Surface_Model are sorted so that the transparency is correct for more than > one overlapping surface (unlike the transpareny in chimera between > models that only works for one level of transparency). You can see > examples that use the _surface module in the GraspSurface, IMOD, > Icosahedron, and Intersurf modules (and others) in the CHIMERA/share > directory of your installation. > > If you have any questions about the _surface module, please ask them on > the chimera developers mailing list, chimera-dev(a)cgl.ucsf.edu. > > Greg Couch > UCSF Computer Graphics Lab > > > ------------------------------ > > _______________________________________________ > Chimera-users mailing list > Chimera-users(a)cgl.ucsf.edu > http://www.cgl.ucsf.edu/mailman/listinfo/chimera-users > > > End of Chimera-users Digest, Vol 57, Issue 24 > ********************************************* >

1 0

VRML alpha vs 1-alpha
by Nils Becker 22 Jan '08

22 Jan '08

Hi, I found information on the web site that VRML models use 1-alpha blending for transparency, and that that looks ugly. I agree. Now I have externally generated VRML files including transparency. Is there a way to get nice (normal) transparency rendering of these models in chimera? e.g. editing the vrml files, converting them to another format or some option inside chimera? Thanks for any help, cheers, Nils

2 1