InterPro domain: IPR045023

This family represents acyl-acyl carrier protein (ACP) thioesterases ([intenz:3.1.2.-]), enzymes from bacteria and plants that control the termination of fatty acid synthesis by hydrolyzing the acyl-ACP complexes and determines the fatty acid profiles produced by an organism [ 1 , 2 , 3 ]. These enzymes are classified as FatA and FatB. FatA thioesterases (or oleoyl-thioesterases) are highly conserved between different plant species and have high specificity for oleoyl-ACP [ 4 ]. Unlike FatA, FatB thioesterases are much more variable and preferentially hydrolyse acyl-ACPs with saturated fatty acyl chains; they can be classified in subfamilies depending on their substrate of preference [ 4 ].

1. Reduced expression of FatA thioesterases in Arabidopsis affects the oil content and fatty acid composition of the seeds. Planta 235, 629-39
2. Identification of active site residues implies a two-step catalytic mechanism for acyl-ACP thioesterase. Biochem J 475, 3861-3873
3. Phylogenetic and experimental characterization of an acyl-ACP thioesterase family reveals significant diversity in enzymatic specificity and activity. BMC Biochem 12, 44
4. Characterization of substrate specificity of plant FatA and FatB acyl-ACP thioesterases. Arch Biochem Biophys 403, 25-34