I have been going over some structure for a group here. When the post-
doc did the originally modeling a number of residues looked to have
alternate conformations. The resolution of the structures are between
2.0 and 1.9 angstroms. My first question is when re-refining in with
an updated version of Refmac the residues with the alternate
conformations become highly disordered. The original version Refmac
used was 5.2.0019 and the new version Refmac is 5.5.0088. I think the
original ccp4 version was 6.0.2 and the latest version of ccp4 is now
being used. All refine runs were done under OS X though on different
processors. As far as I can tell all the input parameters are the
same. Any ideas as to what is going on.
As a followup question, at what point do you actually consider
alternate conformations? The current resolution of these structures
seem to be an a gray area from my perspective, the the density seems
to indicate alternate conformations.
Cheers,
Leonard Thomas Ph.D.
Macromolecular Crystallography Laboratory Manager
University of Oklahoma
Department of Chemistry and Biochemistry
620 Parrington Oval
Norman, OK 73019
[log in to unmask]
http://barlywine.chem.ou.edu
Office: (405)325-1126
Lab: (405)325-7571
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