Visualizing molecular juggling within a B12-dependent methyltransferase complex.

ABSTRACT: Derivatives of vitamin B(12) are used in methyl group transfer in biological processes as diverse as methionine synthesis in humans and CO(2) fixation in acetogenic bacteria. This seemingly straightforward reaction requires large, multimodular enzyme complexes that adopt multiple conformations to alternately activate, protect and perform catalysis on the reactive B(12) cofactor. Crystal structures determined thus far have provided structural information for only fragments of these complexes, inspiring speculation about the overall protein assembly and conformational movements inherent to activity. Here we present X-ray crystal structures of a complete 220 kDa complex that contains all enzymes responsible for B(12)-dependent methyl transfer, namely the corrinoid iron-sulphur protein and its

SUBMITTER: Kung Y 

PROVIDER: S-EPMC3326194 | biostudies-literature | 2012 Mar

REPOSITORIES: biostudies-literature