| Abstract: | We report here the refinement at 2.5-Å resolution of the x-ray crystal structure of bovine seminal ribonuclease, a dimeric covalent enzyme. The protein, which crystallizes with one molecule in the asymmetric unit, consists of two subunits of identical chemical sequences, related by an almost exact binary axis. The tertiary structure of the subunits is similar to that of the pancreatic enzyme, which shows similar catalytic properties. The refinement was carried out using the restrained least-squares procedure both in the reciprocal and real spaces. The assemblage of the subunits in the dimer is described and discussed. |
