Help someone ask a question. * How do CNS deal with the His NE2 atoms coordinated with Zn2+?
Dear all: we have a crystal structure with a Zn2+ tetrahedron coordinated by three His NE2 atoms and one water. Is the proper coordinating distance between three His NE2 atoms and Zn2+ ion is in the range from 1.95-2.1A? But we have not get this result by CNS refinement with parameter_infile 'protein_rep.param and ion.param'. We think that the His NE2 atoms are non-protonated when coordinated with Zn2+, differ from the free His residues. But we don't know how CNS deal with the His NE2 atoms coordinated with Zn2+. How can we get the right coordinating distance? Any help is welcome! Best regards, Deqiang Yao