Two distinct domains contribute to the substrate acyl chain length selectivity of plant acyl-ACP thioesterase

• DOI: 10.1038/s41467-018-03310-z
• Publication Date: 2018-02-22T10:22:05Z
• Authors: Fuyuan Jing; Le Zhao; Marna D. Yandeau-...; Basil J. Nikolau
• Keywords: Thioesterase; Moiety; Acyl carrier protein; Acyl group; Acyl-CoA

The substrate specificity of acyl-ACP thioesterase (TE) plays an essential role in controlling the fatty acid profile produced by type II synthases. Here we identify two groups residues that synergistically determine different specificities TEs from Cuphea viscosissima (CvFatB1 and CvFatB2). One group (V194, V217, N223, R226, R227, I268 CvFatB2) is critical determining structure depth a hydrophobic cavity N-terminal hotdog domain binds substrate's acyl moiety. other (255-RKLSKI-260 285-RKLPKL-289 defines positively charged surface patches may facilitate binding ACP Mutagenesis within these results distinct synthetic efficiently hydrolyze substrates with even shorter chains (C4- to C8-ACPs). These insights into structural determinants TE are useful modifying this enzyme for tailored production engineered organisms.