A DNA fragment, pCKB13, containing two genes encoding Coenzyme a transferase, was isolated from a genomic DNA library of S. marcescens KCTC 2172. The complete nucleotide sequence of the 2,081-bp BamHI fragment on pCKB13 was determined. Sequencing of the fragment led to the identification of two open reading frames showing high homology with two Coenzyme A (CoA) transferases, Acetoacetyl-CoA transferase (Acot) and Succinyl-CoA transferase (Scot), enzymes catalyzing the reversible transfer of CoA from one carboxylic acid to another. The enzyme activity of Coenzyme A transferase increased after introducing the multicopy of the cloned gene in E. coli. The recombinant protein, overexpressed by multicopy and induction with IPTG, was a polypeptide of 42 kDa, as confirmed by SDS-PAGE. The protein was purified to homogeneity through three sequential chromatographic procedures including ion-exchanged DEAE-sepharose, CM-sepharose, and Mono Q.