Members of the CUS family, suspected to be responsible for cutin polymerization, have shown in vitro activity towards sn-2 glyceryl ester (2-MAGs). To assess the selectivity of CUS enzymes towards esters with different headgroups, the CUS1 mediated in vitro polymerization of four monomers of 10,16-dihydroxyhexadecanoic acid was investigated. Our results demonstrated that CUS1 is more selective towards sn-2 glyceryl ester, reinforcing the hypothesis that 2-MAGs are the monomeric precursors of the plant polyester cutin. Additionally, the absence of oxygen atoms in the headgroup negatively impacts the efficiency of polymerization.
- Cutin synthase
- Substrate selectivity