CLONING AND SEQUENCING OF GENES ENCODING MALONATE DECARBOXYLASE IN ACINETOBACTER-CALCOACETICUS

Malonate decarboxylase from Acinetobacter calcoaceticus was isolated a nd characterized (Kim, Y.S., Byun, H.S., J. Biol. Chem. 269 (1994) 296 36-29641), and its subunits were reanalyzed recently to be alpha, beta , gamma, and delta. The genes for the subunits, MdcA (548 a.a.), B (29 5 a.a.), C (238 a.a.), and D (102 a.a.), of the enzyme have been clone d by using oligonucleotide primers deduced from amino acid sequences o f peptides isolated from the purified enzyme, and sequenced to be clus tered in an operon in the order of A-D-B-C. The operon was found to en code more genes than mdcABCD. The Escherichia coli, transformed with t he vector containing the insert mdcADBC and about 1.7 kb of an upstrea m region, expressed the four subunits of the enzyme but the proteins d id not show enzyme activity. It indicates that, like the enzymes from Malonomonas rubra and Klebsiella pneumoniae, more genes are needed for the formation of the functional malonate decarboxylase. (C) 1997 Else vier Science B.V.