Single mutation induces a metal-dependent subunit association in dimeric Cu,Zn superoxide dismutase.

摘要: Tryptophan 83, a residue strongly involved in the intersubunit interaction of Cu,Zn superoxide dismutases from Photobacterium leiognathi, has been selectively mutated to phenylalanine or tyrosine. The recombinant mutant enzymes expressed Escherichia coli were purified two well distinct and stable forms, one dimeric fully active other monomeric devoid metals. In agreement, vitro experiments indicate that removal addition zinc induces monomerization dimerization, respectively, while does not perturb association native protein. This is first unambiguous experimental proof direct communication between interface metal site.