CLONING, SEQUENCING AND EXPRESSION OF THE GENE ENCODING THE COENZYME B-12-DEPENDENT 2-METHYLENEGLUTARATE MUTASE FROM CLOSTRIDIUM-BARKERI INESCHERICHIA-COLI

The coenzyme B-12 (adenosylcobalamin)-dependent 2-methyleneglutarate m utase catalyses the carbon skeleton rearrangement of 2-methyleneglutar ate to (R)-3-methylitaconate in the fermentation of nicotinic acid by the strict anaerobic bacterium Clostridium barkeri. (a) The mgm gene e ncoding 2-methyleneglutarate mutase was cloned and its nucleotide sequ ence was determined. The deduced amino acid sequence revealed a 66.8-k Da protein of 614 amino acids. It shows significant similarity in its C-terminal part to that of other cobamide-dependent enzymes. Probably, this is the coenzyme-binding region.