Hello All,

I am trying to refine some protein structure and right now my structure's R-free is not coming down from 37% even the R-work is lowering in each round of refinements. When phasing done, it created 8 chains for dimer protein (~750 aa's per unit). So I am using NCS for refinement in each cycle. My question is that how to choose the best chains to refine in coot before I do the SSM superpose, Merge and then run the refinement. I am also trying to try auto-build if R-values don't come down. Any suggestions or education is welcomed.

Thanks and cheers.

Chetan Arya

Instem, Bangalore

India 560065