Mechanisms of enzyme catalysis from crystal structure analyses.

Abstract

The enzyme families to which glutathione reductase and adenylate kinase belong show appreciably different structural behaviour during catalysis. While the electron transfer in glutathione reductase requires only small movements of a couple of non-hydrogen atoms, the transfer of a phosphoryl group in the nucleotide kinases involves major rearrangements with main chain displacements of up to 32 A. In both cases, the structural changes during a catalytic cycle have been derived from a number of separate X-ray crystallographic analyses.