Binding of the coenzyme and formation of the transketolase active center

Abstract

Transketolase (TK) is a homodimer, the simplest representative of thiamine diphosphate (ThDP)-dependent enzymes. It was first ThDP-dependent enzymes the crystal structure of which has been solved and revealed the general fold for this class of enzymes and the interactions of the non-covalently bound coenzyme ThDP with the protein component. Transketolase is a convenient model to study the structure(s) of the active center and the mechanism of action of ThDP-dependent enzymes. This review summarizes the results of studies on the kinetics of the interaction of ThDP with TK from Saccharomyces cerevisae as well as the generation of the catalytic-ally active form of the coenzyme within the holoenzyme and formation of the enzyme's active center. © 2005 IUBMB.