cDNA for octopine dehydrogenase (ODH) from the adductor muscle of the great scallop, Pecten maximus, was cloned using 5¢- and 3¢-RACE. The cDNA comprises an ORF of 1197 nucleotides and the deduced amino acid sequence encodes a protein of 399 amino acids. ODH was heterologously expressed inEscherichia coliwith a C-terminal penta His-tag.