Hi there,
Not much information provided. How was the initial model refined ?
Phenix ? It could be a problem with the Refmac refinement protocol
(difficult to say with so little information) if you switched from
Phenix to Refmac.
How certain are you 1 - of the space group; 2 - that the crystal wasn't
twinned ? You can have both and it can be "annoying".
Further, at this resolution I think you could use one of the SHELXes
(forgot the terminology) for refinement, that could be more appropriate.
F.V.
Deepthi wrote:
Hi all
I am working with a small mutant protein which is 56 amino acids long.
The crystal diffracted at 1.4A0 and the space group is p3221. I did
molecular replacement using Phenix software with all the data (1.4A0)
and got a solution. Phenix did auto building with waters and R-free
was 0.3123.
I mutated some residues which don't align with the model protein to
Alanines. When i change the residues back to their respective side
chains Refmac5 won't refine it well. The maps looks clear( you can
guess its 1.4A0 data) but R-free is shooting up to 0.41. It is not
accepting any changes to the Phenix generated model. I have no idea
what is going on. Can anyone help me?
Thank You in advance
Deepthi