- Chimera-users - RBVI Mailing Lists

A features-related question
by Dmitri Pavlov 14 Jan '08

14 Jan '08

Dear friends and colleagues, I have not really tried the product yet, but was wondering whether it is possible to "edit" a protein's structure by introducing one or two single mutations with the follow-up minimization using Chimera. If so, could you please hint to the algorithm of actions. Thanks a lot in advance! The project is burning :-( Dmitri

1 0

transparent background
by Krepkiy, Dmitriy (NIH/NINDS) [F] 14 Jan '08

14 Jan '08

Hi, Is it possible to make background transparent? Thanks, Dmitriy ************************************** Dmitriy Krepkiy, Ph.D. Room 3B213 Building 35 - Porter Bldg, 35 Convent Dr Bethesda, MD 20892

2 1

Fit model in map algorithm
by Tom Goddard 14 Jan '08

14 Jan '08

Christopher Akey wrote: > Tom- > > I was wondering how the fit model into map works? Is it calculating a > ccf and if so how since a pdb and a map file are quite different > entities. > > > cheers C Akey Hi Christopher, The Chimera fit model in map capability does a rigid rotation and translation to maximize the sum of the map values at the atom positions. It reports the average map value at the atom positions. It doesn't report a correlation coefficient. That would require calculating a simulated map from the PDB at the desired resolution and Chimera currently cannot do that. I would like to add that capability since correlation values are the standard measure of goodness of fit that is reported in the literature. The fit model in map code uses a gradient ascent iterative method to maximize the sum of map values. The Chimera fit map in map capability will report a correlation value. So you could run some external program to compute a simulated map (I've used pdb2mrc from the EMAN package) then fit that simulated map into your experimental map with the fit map in map dialog and get a correlation value. Or you could use the Chimera fit model in map to fit the PDB, then open the simulated map, register it with the fit PDB (using Model Panel / Transform As button), and then have the fit map in map dialog report the correlation without optimizing the simulated map placement. I'd expect very similar results from fitting the PDB versus fitting the simulated map. The fit map in map algorithm maximizes the "overlap" between maps. That is not the same as the correlation. It is a sum of the pointwise products between the two maps at grid points within the contour surface of one of the maps. That differs from the correlation in that it is not normalized by the sum of the squares of each maps' values within the surface. This has important consequences. The Chimera "overlap" optimization will move the map into a nearby high density region even if the pattern of highs and lows in the density does not match. The correlation normalization eliminates the tendency to move to higher density -- instead just optimizing the match of the highs and lows in the density. Both are useful and I will in the future add an option to optimize the correlation. The Tools section of the Chimera User's Guide describes the map and model fitting methods: http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/fitmodels/fitmodel… http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/fitmaps/fitmaps.ht… Tom

1 0

Re: [Chimera-users] suppressing warning messages
by Eric Pettersen 08 Jan '08

08 Jan '08

Hi Ryan, Perhaps other Chimera developers can chime in, but I don't know of any good way to selectively suppress the non-status messages that Chimera generates, particularly the "duplicate atom serial number" messages which are being put on standard error by code in the C++ layer. What I can suggest in your situation is that you have your print statements go to standard error (so that they flush through pipes immediately) and that you prefix them with some unique string that you can grep for. Something like: from sys import __stderr__ as stderr print>>stderr, "OUTPUT", "my result:", r and run Chimera with: chimera --nogui myscript.py |& grep OUTPUT --Eric On Jan 8, 2008, at 12:19 PM, Ryan Pavlovicz wrote: > Are there ways just to suppress the chimera output? I'd still like > to see some of my print commands that are part of my python script, > so i can easily debug, follow a process, etc.? > > On Jan 8, 2008 1:24 PM, Eric Pettersen < pett(a)cgl.ucsf.edu> wrote: > Well to suppress all output you would use normal shell redirection > to /dev/null. For csh-style shells, something like this: > > chimera --nogui >& /dev/null > > --Eric > > Eric Pettersen > UCSF Computer Graphics Lab > http://www.cgl.ucsf.edu > > > On Jan 8, 2008, at 9:28 AM, Ryan wrote: > >> The --nostatus option will suppress messages like: >> >> "Executing xxx.py... Opening xxx.pdb..." >> >> but still, messages like: >> >> "Model 0 (xxx.pdb) appears to be a protein with noe secondary >> structure assignements. Computing assignments..." & "warning: >> duplicate atom serial number found..." >> >> are still printed to the screen. Are there ways to suppress these >> messages as well? Thanks again, >> >> ryan >> >> >> _______________________________________________ >> Chimera-users mailing list >> Chimera-users(a)cgl.ucsf.edu >> http://www.cgl.ucsf.edu/mailman/listinfo/chimera-users > >

1 0

Re: [Chimera-users] suppressing warning messages
by Ryan 08 Jan '08

08 Jan '08

The --nostatus option will suppress messages like: "Executing xxx.py... Opening xxx.pdb..." but still, messages like: "Model 0 (xxx.pdb) appears to be a protein with noe secondary structure assignements. Computing assignments..." & "warning: duplicate atom serial number found..." are still printed to the screen. Are there ways to suppress these messages as well? Thanks again, ryan

2 1

suppressing warning messages
by Ryan 08 Jan '08

08 Jan '08

Is there a way to suppress warning messages when using Chimera in a python script (--nogui option)? Additionally, is there a way to suppress the additional non-warning Chimera output that prints to screen when running via python script? Thanks, ryan

2 1

How to input more than one mdcrd file
by Francesco Pietra 07 Jan '08

07 Jan '08

I was unable to input more that one mdcrd file to MD Movie (to get a single pdb file for EnsembleCluster). I tried by either giving the files one to one, or with the following prod.meta: amber my.prmtop prod1.mdcrd.gz prod2.mdcrd.gz prod3.mdcrd.gz Always, I got prod1 trajectories alone. I used compressed coordinate files also when fed one to one. I did not try with non compressed files. Thanks francesco pietra ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping

2 1

chimera crashes my linux 64 bits PC
by jean-francois menetret 07 Jan '08

07 Jan '08

After I rebooted my linux 64 bits PC this morning, chimera crashes the machine. I tried older versions of chimera ... same result :-( How can I fix that situation ? Jean-Fran�ois M�n�tret, PhD Boston University School of Medicine Physiology and Biophysics Department 700 Albany Street W315 Boston, MA 02118 Email: menetret(a)bu.edu Mailing address: 715 Albany Street

2 1

mean structure
by sette＠uniroma2.it 07 Jan '08

07 Jan '08

Hi, I don't know if someone already ask for this... It is possible to calculate an average structure having a bundle of structures? I loaded from the pdb a file containing 30 NMR structures but I would like to use only the mean structure... Thanks for your help, Marco Dr.Marco Sette, Ph.D. Department of Chemical Sciences and Technology University of Rome, "Tor Vergata" via della Ricerca Scientifica, 00133, Rome, Italy e-mail: sette(a)uniroma2.it Tel.: +39-0672594424 Fax: +39-0672594328

2 1

Slow dealing with pdb files
by Francesco Pietra 03 Jan '08

03 Jan '08

I am dealing with the average structure (a protein complex embedded in a POCP membrane and water solvated) derived with Amber's ptraj from a 1.5 ns MD. Opening this pdb file in 1.2470 Chimera has become extremely slow. The file is 6.4MB. First, below the screen it is warned "Ignored bad PDB record found on line #", for lines from 1 to 114154. This may take some 10 minutes. The pdb records read as in the following examples: For the lipid: ATOM 20 2C21 POP 1 25.569 20.201 48.492 0.00 0.00 For the protein: ATOM 10915 HB2 ALA 117 44.211 74.567 28.832 0.00 0.00 For water: ATOM 22264 O WAT 1771 25.558 39.417 16.580 0.00 0.00 ATOM 22265 H1 WAT 1771 25.582 39.432 16.549 0.00 0.00 ATOM 22266 H2 WAT 1771 25.569 39.482 16.611 0.00 0.00 After that, the warning message changes to "Computed secondary structure assignments (see reply log)" which lasts for longer than 1 hour and 20 minutes. During this time, "top" command shows that python is using 12% MEM and 99% CPU. Then, the graphics appears, with the membrane-protein-complex not centered in the water box. During all that time, I had to avoid doing anything else with the GNOME interface. A second terminal for "top" had to be opened before launching Chimera on another terminal window. Otherwise, spurious graphics become superimposed to the Chimera window. I could then carry out rapid mapping of the protein residues around the single-residue ligand (select protein & :ligandname z<#), which was what I wanted to do. The same events occurred with shorter trajectories. At ca 0.7ns the time taken by Chimera to work out the average-structure pdb was about 15 minutes. Clearly, there is an exponential trend. I can in part compare these events on VMD: the pdb file from 1.5ns MD is opened in VMD in less than 1 minute and the resulting membrane-protein-complex is centered in the water box. Is all that caused by the not-updated atom naming by Amber? Or could the execution be accelerated by calling some C routines by python? Chimera was run on a modest desktop: Athlon 1GHz, RAM 1GB, a poor main board (product: K7S5A, vendor: ECS, version: 1.0), Debian Linux i386. 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 4