Properties and sequence of the coenzyme B12-dependent glycerol dehydratase of Clostridium pasteurianum

The genes encoding coenzyme B-12-dependent glycerol dehydratase of Clos:Clostridium pasteurianum were subcloned and expressed in Escherichia coli. The native molecular mass of the enzyme is 190 000 Da. The enzyme converts glycerol, 1,2-propanediol and 1.2-ethanediol to 3-hydroxypropionaldehyde, propionaldehyde and acetaldehyde, respectively, but glycerol is the preferred substrate. The nucleotide sequences of the dhaBCE genes encoding the three subunits of glycerol dehydratase and of orfZ whose function is unknown were determined. The deduced products of the dhaBCE genes with calculated molecular masses of 60 813. 19 549 and 16 722 Da, respectively, revealed high similarity to amino acid sequences of subunits of coenzyme B-12-dependent glycerol and diol dehydratases from other organisms. (C) 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.