difference in B factor for NCS groups
Dear all, I'm working with a structure were one NCS copy has significantly high B-factors than the other. That one copy makes few crystal contacts to stabilize it. Is there a recommended way to adjust the refinement to reflect this ... using TLS? Decreasing b_factor_weight? Is there a way refine a group_b to be added to the b-factor of each atom in that chain? --James
Using TLS is the appropriate way to handle this situation. The restraints between NCS related atoms (if you are using NCS restraints) will be applied to the residual ADPs, not the total (i.e. the TLS should account for the difference in overall B for the molecules). On Aug 21, 2009, at 8:17 AM, James Whittle wrote:
Dear all,
I'm working with a structure were one NCS copy has significantly high B-factors than the other. That one copy makes few crystal contacts to stabilize it.
Is there a recommended way to adjust the refinement to reflect this ... using TLS? Decreasing b_factor_weight? Is there a way refine a group_b to be added to the b-factor of each atom in that chain?
--James _______________________________________________ phenixbb mailing list [email protected] http://www.phenix-online.org/mailman/listinfo/phenixbb
-- Paul Adams Acting Division Director, Physical Biosciences Division, Lawrence Berkeley Lab Adjunct Professor, Department of Bioengineering, U.C. Berkeley Vice President for Technology, the Joint BioEnergy Institute Head, Berkeley Center for Structural Biology Building 64, Room 248 Tel: 1-510-486-4225, Fax: 1-510-486-5909 http://cci.lbl.gov/paul Lawrence Berkeley Laboratory 1 Cyclotron Road BLDG 64R0121 Berkeley, CA 94720, USA. Executive Assistant: Patty Jimenez [ [email protected] ] [ 1-510-486-7963 ] --
Hi James, to add to Paul's reply, I would also try using the weight optimization for B-factors refinement to see how much difference it makes (use "optimize_wxu=true" keyword for this). Since it may take longer (sometime significantly longer) than a regular refinement run, you may want to try it once or as the final refinement step. Pavel. On 8/21/09 8:17 AM, James Whittle wrote:
Dear all,
I'm working with a structure were one NCS copy has significantly high B-factors than the other. That one copy makes few crystal contacts to stabilize it.
Is there a recommended way to adjust the refinement to reflect this ... using TLS? Decreasing b_factor_weight? Is there a way refine a group_b to be added to the b-factor of each atom in that chain?
--James _______________________________________________ phenixbb mailing list [email protected] http://www.phenix-online.org/mailman/listinfo/phenixbb
participants (3)
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James Whittle
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Paul Adams
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Pavel Afonine