The significant high 46% free R vs 17% R value
may indicate inaccurate rotation angles and translation
vectors, or missed internal domain angles.
We experienced an wrong MR solution with 48% free R vs 23% R
at 3.5A resolution (Brady & Jiang, CCP4 Study Weekend, 1992),
where the internal domain angle was missed about 13 degrees
("elbow" angle of Fab domains) though the overall orientation
was only 5 degrees difference.
Suggestions in addition to Dave Schuller's:
1. Try more rigid-body refinements and construct more
internal groups (if any flexible domain) for PC refinement.
2. Try different resolution cut-off to see whether the MR
solution persists. Higher resolution data may improve the
accuracy of MR solution.
3. Use STRICK NCS constraint rather than use RESTRAINT NCS
in SA refinement if any NCS exsits.
Jiansheng Jiang.
jiang at laplace.csb.yale.edu
