Hello, I am refining a 3.5 Å structure using the latest stable version of Phenix.Refine. After switching to the latest version the Bond RMSDs exploded to ~ 0.035 Å, when using optimize wxc. Turning off Optimize and using the "Fix WXC" parameters in the GUI with increasingly smaller values had almost no effect on the final bond rmsds, which seems to explode from reasonable values in the "3_xyz" step of refinement. Am I missing something? Best regards, Mark Mark Andrew White, Ph.D. Associate Professor of Biochemistry & Molecular Biology, Manager, SCSB Macromolecular X-ray Laboratory UTMB, Galveston, TX http://xray.utmb.edu
Mark
Pavel is best to answer this but he will return on Thursday. Someone else
may offer guidance until then.
Cheers
Nigel
---
Nigel W. Moriarty
Building 33R0349, Molecular Biophysics and Integrated Bioimaging
Lawrence Berkeley National Laboratory
Berkeley, CA 94720-8235
Phone : 510-486-5709 Email : [email protected]
Fax : 510-486-5909 Web : CCI.LBL.gov
On Mon, Aug 10, 2020 at 1:10 PM White, Mark
Hello,
I am refining a 3.5 Å structure using the latest stable version of Phenix.Refine. After switching to the latest version the Bond RMSDs exploded to ~ 0.035 Å, when using optimize wxc. Turning off Optimize and using the "Fix WXC" parameters in the GUI with increasingly smaller values had almost no effect on the final bond rmsds, which seems to explode from reasonable values in the "3_xyz" step of refinement. Am I missing something?
Best regards, Mark
Mark Andrew White, Ph.D. Associate Professor of Biochemistry & Molecular Biology, Manager, SCSB Macromolecular X-ray Laboratory UTMB, Galveston, TX http://xray.utmb.edu _______________________________________________ phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb Unsubscribe: [email protected]
Hi Mark,
While waiting for Pavel to return, you could do the following:
Check if the rmsd goes up because all bond rmsds increase or because there
are a few outrageous outliers. The validation tab after refinement lists
the worst offenders for geometry restraints.
Best wishes,
Dorothee
On Mon, Aug 10, 2020 at 3:12 PM Nigel Moriarty
Mark
Pavel is best to answer this but he will return on Thursday. Someone else may offer guidance until then.
Cheers
Nigel
--- Nigel W. Moriarty Building 33R0349, Molecular Biophysics and Integrated Bioimaging Lawrence Berkeley National Laboratory Berkeley, CA 94720-8235 Phone : 510-486-5709 Email : [email protected] Fax : 510-486-5909 Web : CCI.LBL.gov
On Mon, Aug 10, 2020 at 1:10 PM White, Mark
wrote: Hello,
I am refining a 3.5 Å structure using the latest stable version of Phenix.Refine. After switching to the latest version the Bond RMSDs exploded to ~ 0.035 Å, when using optimize wxc. Turning off Optimize and using the "Fix WXC" parameters in the GUI with increasingly smaller values had almost no effect on the final bond rmsds, which seems to explode from reasonable values in the "3_xyz" step of refinement. Am I missing something?
Best regards, Mark
Mark Andrew White, Ph.D. Associate Professor of Biochemistry & Molecular Biology, Manager, SCSB Macromolecular X-ray Laboratory UTMB, Galveston, TX http://xray.utmb.edu _______________________________________________ phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb Unsubscribe: [email protected]
_______________________________________________ phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb Unsubscribe: [email protected]
-- Project Scientist, Molecular Biophysics and Integrated Bioimaging Lawrence Berkeley National Laboratory 1 Cyclotron Road, M/S 33R0345 Berkeley, CA 94720 Tel: (510) 486-5709 Fax: (510) 486-5909 Web: https://phenix-online.org
Everyone,
The problem seems to relate to using Real Space Refinement in phenix.refine, which at the final stages of refinement I usually turn off, but did not this time. Turning off XYZ (real-space) in the GUI allows WXC to work properly.
This does seem to indicate a bug in the WXC optimization routine. Years ago I implemented an optimization scheme in CNS based on target Bond-RMSD values which can be roughly related to the number of observations / number of atoms ~ (#reflections>5sigma)/(#atoms). The target can then be limited to physically reasonable values 0.004 < Bond-RMSD < 0.025, and you never see a bond RMSD of 0.035 Å.
Best regards,
Mark
Mark Andrew White, Ph.D.
Associate Professor of Biochemistry & Molecular Biology,
Manager, SCSB Macromolecular X-ray Laboratory
UTMB, Galveston, TX
http://xray.utmb.edu
________________________________
From: Dorothee Liebschner
Hi Mark,
I am refining a 3.5 Å structure using the latest stable version of Phenix.Refine. After switching to the latest version the Bond RMSDs exploded to ~ 0.035 Å, when using optimize wxc. Turning off Optimize and using the "Fix WXC" parameters in the GUI with increasingly smaller values had almost no effect on the final bond rmsds, which seems to explode from reasonable values in the "3_xyz" step of refinement. Am I missing something?
does this happen in one of the latest nightly builds? I fixed a few bugs shortly after the official release and I think these may be related. If you are still seeing this problem please send me inputs and I will investigate. Pavel
participants (4)
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Dorothee Liebschner
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Nigel Moriarty
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Pavel Afonine
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White, Mark