title: Outer-sphere residues influence the catalytic activity of a chalcone synthase from Polygonum cuspidatum.
abstract: We have previously cloned a chalcone synthase (PcCHS1) from Polygonum cuspidatum and biochemically identified its enzymatic dynamic properties. Here, we found that the outer sphere residues, Q82 and R105, could affect the catalytic activity and product profile of PcCHS1. Both Q82P and R105Q mutations of PcCHS1 could also change the pH dependence activity as well as the product profile of PcCHS1. Moreover, the Q82P/C198F double mutant could rescue the complete loss of enzyme activity caused by the C198F single mutation. Our study demonstrated that these outer-sphere residues of PcCHS1 play important roles both in structural maintenance and enzyme activity.
authors.affiliation: University of Chinese Academy of Sciences Beijing China.
authors.forename: Yalin
authors.initials: Y
authors.lastname: Shen
authors.affiliation: University of Chinese Academy of Sciences Beijing China; State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China.
authors.forename: Xing
authors.initials: X
authors.lastname: Li
authors.affiliation: University of Chinese Academy of Sciences Beijing China.
authors.forename: Tuanyao
authors.initials: T
authors.lastname: Chai
authors.affiliation: University of Chinese Academy of Sciences Beijing China.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
keywords: Polygonum cuspidatum; chalcone synthase; site‐directed mutagenesis