Cloning and expression in Escherichia coli of a cDNA coding for the oleoyl-acyl carrier protein thioesterase from coriander (Coriandrum sativum L.).

A cDNA for the oleoyl-acyl carrier protein (ACP) thioesterase (E.C. 3.1.2.14) from coriander seed endosperm (Coriandrum sativum) was isolated using a safflower oleoyl-ACP thioesterase cDNA probe. The coriander cDNA coded for a 42.3 kDa protein including a putative 40 amino acid plastid targeting transit peptide. The gene was expressed in Escherichia coli and the recombinant protein was isolated to homogeneity by alkyl-ACP affinity and anion-exchange chromatography. The pure protein showed a high thioesterase activity for oleoyl-ACP vs. other acyl-ACPs and therefore was identified as the coriander oleoyl-ACP thioesterase. Antibodies were raised against the recombinant protein and used to detect the coriander thioesterase in enriched endosperm fractions.