Dear BB, I am attempting molecular replacement with a 2.8A data set from crystals of a coiled coil of about 150 residues. Probably p21212 but maybe p2221.
So far, Phaser, MolRep, Amore, Mr Bump, have not provided a good solution as judged by Z-scores, CCs, Rfactors, and whether there is any density outside the model (there should be - I'm using a slightly shorter model to search with). One possible problem is that the coiled coil may not be straight. It may have a slight curve to it. I have used models from the PDB that are straight or slightly curved, so far with no success. I have tried a few different resolution cutoffs too. I have tried single helix chains or dimeric coiled coils. Is there anything special about MR with coiled coils? Can anybody provide any tips/hints on MR with coiled coils?? Thanks Ed
