Molecular and biochemical characterisation of Mycobacterium smegmatis alcohol dehydrogenase C

The gene encoding of an alcohol dehydrogenase C (ADHC) from Mycobacterium s megmatis was cloned and sequenced. The protein encoded by this gene has 78% identity with Mycobacterium tuberculosis and Mycobacterium bovis BCG ADHC. The M. smegmatis ADHC was purified from M. smegmatis and the kinetic param eters of this enzyme showed that using NADPH as electron donor it has a str ong preference for aliphatic and aromatic aldehyde substrates. Like the M. bovis BCG ADHC, this enzyme is more likely to act as an aldehyde reductase than as an alcohol dehydrogenase. The discovery of such an ADHC in a fast-g rowing, and easily engineered mycobacterial species opens the way to the ut ilisation of this M, smegmatis enzyme as a convenient model for the study o f the physiological role of this alcohol dehydrogenase in mycobacteria. (C) 2001 Federation of European Microbiological Societies. Published by Elsevi er Science B.V. All rights reserved.