Cyclohexane-1,2-dione hydrolase: A new tool to degrade alicyclic compounds

Abstract

Alicyclic alcohols are naturally occurring compounds which can be degraded by microorganisms via cleavage of the ring C-C bond. Denitrifying Azoarcus sp. strain 22Lin grows on cyclohexane-1,2-diol which serves as electron donor and carbon source. The diol is converted to cyclohexane-1.2-dione followed by hydrolysis to the corresponding semialdehyde and oxidation to adipate. The latter two reactions are catalyzed by the thiamine diphosphate-dependent flavoenzyme cyclohexane-1,2-dione hydrolase, the first a-ketolase known so far. Biochemical and structural properties of this new member of the thiamine diphosphate enzyme family will be presented. (C) 2009 Elsevier B.V. All rights reserved.