Engineering of a thermostable esterase Est816 to improve its quorum-quenching activity and the underlying structural basis.

ABSTRACT: N-acyl-homoserine lactones (AHLs) are small diffusible molecules called autoinducers that mediate cell-to-cell communications. Enzymatic degradation of AHLs is a promising bio-control strategy known as quorum-quenching. To improve the quorum-quenching activity of a thermostable esterase Est816, which had been previously cloned, we have engineered the enzyme by random mutagenesis. One of the mutants M2 with double amino acid substitutions (A216V/K238N) showed 3-fold improvement on catalytic efficiency. Based on the crystal structure determined at 2.64 Å, rational design of M2 was conducted, giving rise to the mutant M3 (A216V/K238N/L122A). The k_cat/K_M value of the mutant M3 is 21.6-fold higher than that of Est816. Furthermore, activity assays demonstrated that M3 reach

SUBMITTER: Liu X 

PROVIDER: S-EPMC5133562 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature