R=50% at a resolution of 2.2 Å is a lot different to 50% at, say, 3.5 Å
resolution. What happens if you refine it at 3.0 or 3.5 Å ?
What's the model vs sequence % identity ?
Phil Jeffrey
Princeton
On 11/17/17 3:23 PM, Yue Li wrote:
Dear all,
I have several datasets (one best resolution reaching 2.2A), giving C2
space group, two molecules in an asymmetry unit (65.1% of solvent
content). When running MR using a template (<20% sequence identify to
the target molecule), I got a solution with high TFZ (23.7) and LLG
(842). However, the Rfree sticks to 50% in the structural refinement
using phenix. There is no complain in Xtriage - no twin, no
translational NCS. I think that the structure solution looks
reasonable, which can explain the three disulfide bond formations
through the sequence threading. I tried to search three molecules in
the asymmetry unit, but the final solution gives me two molecules.
Do you have any suggestion for this high Rfree problem?
Thank you very much for your help.
All the very best,
Simon
