The Crystal Structure of Bovine Cu2+,Zn2+ Superoxide Dismutase at 5.5-A Resolution

Abstract

An electron density map at 5.5-A resolution has been obtained of bovine erythrocyte Cu2+,Zn2+ superoxide dismutase. The asymmetric unit of the crystal contains 2 enzyme molecules, each made up of two subunits related by an internal local 2-fold axis. As seen at this resolution all four subunits have the same conformation: extensive b structure appears to surround a central cylindrical hydrophobic core, and there are no readily identifiable stretches of α helix. Heavy atom replacement results imply a possible location for the Zn2+.