Dear List, Sorry fo r the easy question, but I have a problem with Autobuild. I'm trying to rebuild a scFv, composed of two domains linked by a linker. I've managed to find an MR solution with a polyalanine model deprived of the loops, which is my starting model for rebuilding. I've given Autobuild three input files: the mtz, the model coordinates and the sequence of the scFv, asking to model only the beta strands and helices. Problem is that in the final model Autobuild seems to guess incorrectly the density of two beta-strands, inserting the linker there instead of the expected side chains. Any suggestions on how to correct this? Shall I manually rebuild this part to avoid problems? Or is it crucial to prevent errors, for example, that the model and the sequence are numbered so that they are in register? Thanks in advance, Claudia Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673 _________________________________________________________________ Hotmail: Trusted email with powerful SPAM protection. https://signup.live.com/signup.aspx?id=60969
Hi Claudia, To carry on from where you are, I would recommend fixing by hand any things that you can see are incorrect. If you know that the loops have been built connecting the wrong chains then I would definitely fix that. If the sequence has been incorrectly assigned I would fix that too. Your hand-fixed model can then be the starting point for another round of AutoBuild, either with "rebuilding_in_place=False" to try and add more backbone model, or with "rebuild_in_place=True" to just try to make a better fit of the model that you have built. You can then use "phenix.fit_loops" to try and fill in loops that have not yet been built. You might also try another approach from the beginning of model-building by starting with the MR model without trimming to poly-Ala. You might alternatively try the new Sculptor tools in the current PHENIX to set up your starting model. I am guessing that you may have a relatively low-resolution map as you have chosen to use "helices_strands_only=True". You might want to follow a different path and just use "rebuild_in_place=True" from the beginning, then cut out all the places where the starting model had the wrong sequence, and then use fit_loops to fill in these places. The advantage of this approach is that rebuild_in_place=True keeps your overall model, only adjusting where the main-chain goes and rebuilding side-chains from the Richardson rotamer library. If AutoBuild is doing a poor job at building your model from scratch then this might be a useful approach. All the best, Tom T
Dear List,
Sorry fo r the easy question, but I have a problem with Autobuild.
I'm trying to rebuild a scFv, composed of two domains linked by a linker.
I've managed to find an MR solution with a polyalanine model deprived of the loops, which is my starting model for rebuilding.
I've given Autobuild three input files: the mtz, the model coordinates and the sequence of the scFv, asking to model only the beta strands and helices.
Problem is that in the final model Autobuild seems to guess incorrectly the density of two beta-strands, inserting the linker there instead of the expected side chains.
Any suggestions on how to correct this? Shall I manually rebuild this part to avoid problems? Or is it crucial to prevent errors, for example, that the model and the sequence are numbered so that they are in register?
Thanks in advance,
Claudia
Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673
_________________________________________________________________ Hotmail: Trusted email with powerful SPAM protection. https://signup.live.com/signup.aspx?id=60969________________________________... phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb
I'm guessing the helices_strands.pdb file got corrupted somehow. Does phenix.pdb.hierarchy helices_strands.pdb give clues? Ralf
From: Jobichen Chacko
To: PHENIX user mailing list Sent: Tue, January 11, 2011 8:50:09 PM Subject: [phenixbb] Problem with Autobuild Dear All, I am trying to run Phenix autobuild using the helices-strands.pdb obtained using find helices and strands program. But the program is not running with the following error message. The file helices_strands.pdb does not seem to be a PDB file
Thanks. Jobi
Dear Ralf,
Please see the result from hierarchy run.
phenix.pdb.hierarchy helices_strands .pdb
file helices_strands.pdb
total number of:
models: 1
chains: 1
alt. conf.: 0
residues: 540
atoms: 540
anisou: 0
number of atom element+charge types: 1
histogram of atom element+charge frequency:
" " 540
residue name classes:
"common_amino_acid" 540
number of chain ids: 1
histogram of chain id frequency:
" " 1
number of alt. conf. ids: 0
number of residue names: 1
histogram of residue name frequency:
"GLY" 540
Thanks.
Jobi
On Wed, Jan 12, 2011 at 2:04 PM, Ralf W. Grosse-Kunstleve
I'm guessing the helices_strands.pdb file got corrupted somehow. Does
phenix.pdb.hierarchy helices_strands.pdb
give clues?
Ralf
*From:* Jobichen Chacko
*To:* PHENIX user mailing list *Sent:* Tue, January 11, 2011 8:50:09 PM *Subject:* [phenixbb] Problem with Autobuild Dear All, I am trying to run Phenix autobuild using the helices-strands.pdb obtained using find helices and strands program. But the program is not running with the following error message. The file helices_strands.pdb does not seem to be a PDB file
Thanks. Jobi
_______________________________________________ phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb
Hi Jobi, I think that your helices_strands.pdb is a CA-only trace. If so, then it is true that autobuild cannot make use of it. My guess is that helices_strands.pdb came from phenix.find_helices_strands mymap.mtz which will produce a CA trace using the trace_chain algorithm. Can you possibly try instead: phenix.find_helices_strands trace_chain=False mymap.mtz which will do more of what you want. I am thinking of changing the default back to "trace_chain=False" so that you won't be misled in the future... All the best, Tom T
Dear Ralf, Please see the result from hierarchy run.
phenix.pdb.hierarchy helices_strands .pdb file helices_strands.pdb total number of: models: 1 chains: 1 alt. conf.: 0 residues: 540 atoms: 540 anisou: 0 number of atom element+charge types: 1 histogram of atom element+charge frequency: " " 540 residue name classes: "common_amino_acid" 540 number of chain ids: 1 histogram of chain id frequency: " " 1 number of alt. conf. ids: 0 number of residue names: 1 histogram of residue name frequency: "GLY" 540
Thanks. Jobi
On Wed, Jan 12, 2011 at 2:04 PM, Ralf W. Grosse-Kunstleve
wrote: I'm guessing the helices_strands.pdb file got corrupted somehow. Does
phenix.pdb.hierarchy helices_strands.pdb
give clues?
Ralf
*From:* Jobichen Chacko
*To:* PHENIX user mailing list *Sent:* Tue, January 11, 2011 8:50:09 PM *Subject:* [phenixbb] Problem with Autobuild Dear All, I am trying to run Phenix autobuild using the helices-strands.pdb obtained using find helices and strands program. But the program is not running with the following error message. The file helices_strands.pdb does not seem to be a PDB file
Thanks. Jobi
_______________________________________________ phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb
_______________________________________________ phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb
participants (4)
-
Claudia Scotti
-
Jobichen Chacko
-
Ralf W. Grosse-Kunstleve
-
Thomas C. Terwilliger