5ypt

Publication Abstract from PubMed

Chalcone synthases (CHSs) of the type III polyketide synthases (PKSs), catalyze the formation of a tetraketide intermediate from a CoA-tethered starter and malonyl-CoA but use different cyclization mechanisms to produce distinct chemical scaffolds. Herein, we characterized CHS and CHS-like enzymes (designated MpCHS and MpCHSL1, 2 and 3) from Marchantia paleacea and determined the crystal structure of MpCHSL1. MpCHS catalyzed a Claisen condensation to form chalcone, while MpCHSLs catalyzed the formation of lactonized alpha-pyrones in vitro. Based on the structural, mutational and in vitro biochemical analyses, we established that MpCHSL1 is structurally and functionally closer to prototype CHS than stilbene synthase, and characterized the structural basis for the functional diversity of the type III PKSs. A chalcone-forming mutant of MpCHSL1 was build directed by the structural information. These findings pave the way for future studies to elucidate the functional diversity of type III PKSs in liverwort.

Structural and biochemical characterization of the plant type III polyketide synthases of the liverwort Marchantia paleacea.,Yu HN, Liu XY, Gao S, Sun B, Zheng HB, Ji M, Cheng AX, Lou HX Plant Physiol Biochem. 2018 Apr;125:95-105. doi: 10.1016/j.plaphy.2018.01.030., Epub 2018 Jan 31. PMID:29428820^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.