Re: [ccp4bb] How do I set up a Refmac5 dictionary to constrain octahedrally coordinated Ca++

[Roger Rowlett]

Pietro, You will need to set "Make links between: All others if...residues are close only" in the Refmac GUI and write out a .cif file for the Ca-ligand distance restraints. See this link: http://capsicum.colgate.edu/chwiki/tiki-index.php?page=Model+Refinement#Restraining_metal_ligand_distances_during_refinement_in_REFMAC Cheers. Pietro Roversi wrote: Dear all, How do I set up a Refmac dictionary to constrain octahedrally coordinated Ca++? Refmac5 seems to detect the potential bond between the Ca++ and the ligands: INFO: link is found (not be used) dist= 2.229 ideal_dist= 2.320 ch:AA res: 263 GLU at:O .->ch:Ag res: 600 CA at:CA . but it does not enforce them, and I cannot figure out what the CCP4 convention for a O-Ca++ bond is. Thanks for any suggestions! Pietro -- Roger S. Rowlett Professor Department of Chemistry Colgate University 13 Oak Drive Hamilton, NY 13346 tel: (315)-228-7245 ofc: (315)-228-7395 fax: (315)-228-7935 email: rrowl...@mail.colgate.edu