Cloning of Acyl-ACP Thioesterase FatA fromArachis hypogaeaL. and Its Expression inEscherichia coli

In this study, a full-length cDNA of the acyl-ACP thioesterase,AhFatA, was cloned from developing seeds ofArachis hypogaeaL. by 3′-RACE. Sequence analysis showed that the open reading frame encodes a peptide of 372 amino acids and has 50–70% identity with FatA from other plants. Real-time quantitative PCR analysis revealed thatAhFatA was expressed in all tissues ofA. hypogaeaL., but most strongly in the immature seeds harvested at 60 days after pegging. Heterologous expression ofAhFatA inEscherichia coliaffected bacterial growth and changed the fatty acid profiles of the membrane lipid, resulting in directed accumulation towards palmitoleic acid and oleic acid. These results indicate that AhFatA is at least partially responsible for determining the high palmitoleic acid and oleic acid composition ofE. coli.