Greetings fellow Crystallographers, I'm working on a structure at 1.8-A resolution that contains an acetone crosslink between 2 cysteines (crosslink was incorporated by adding 1,3-dichloroacetone). I figured that the easiest way to model this is to mutate one of the cysteines to S-acetonylcysteine (CSA in the PDB) and then link it to the other cys. I've seen how to do this in COOT using the mutate-by-overlap function; however, CSA is of course not in the CCP4 library that is installed on our system. I've built restraints for CSA using phenix.elbow and tried importing the residue into COOT that way, still to no avail. So I figured the way to go now is to import the cif file directly into the LIBCHECK library in our system and then I should (in theory) be able to use mutate-by-overlap to place the residue. However, this is where I'm stuck. I can't seem to figure out the notation for importing the cif file into LIBCHECK. I tried using FILE_CIF CSA.cif and I get an error "reading title of input file." What am I doing wrong? Is there another approach I should consider? Any help or advice would be greatly appreciated.
Cheers, Geoff -- Geoffrey K. Feld Department of Chemistry 492 Stanley Hall University of California, Berkeley "Vigilia pretium libertatis"
