文献类型：期刊文献

英文题名：LysR-type transcriptional regulator metr controls prodigiosin production, methionine biosynthesis, cell motility, H2O2 tolerance, heat tolerance, and exopolysaccharide synthesis in serratia marcescens

作者：Pan, Xuewei[1]; Sun, Changhao[1]; Tang, Mi[1]; You, Jiajia[1]; Osire, Tolbert[1]; Zhao, Youxi[2]; Xu, Meijuan[1]; Zhang, Xian[1]; Shao, Minglong[1]; Yang, Shangtian[3]; Yang, Taowei[1]; Raoa, Zhiming[1]

第一作者：Pan, Xuewei

通讯作者：Yang, Taowei

机构：[1] Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi, China; [2] Biochemical Engineering College, Beijing Union University, Beijing, China; [3] Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, United States

第一机构：Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi, China

通讯机构：[1]Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi, China

年份：2020

卷号：86

期号：4

外文期刊名：Applied and Environmental Microbiology

收录：EI(收录号：20201008253041);Scopus(收录号：2-s2.0-85079022569)

语种：英文

外文关键词：Mammals - Antimicrobial agents - Polymerase chain reaction - Amino acids - Biochemistry - Biosynthesis - Gene encoding - Biofilms - Electrophoretic mobility - Metabolites - Transcription

摘要：Prodigiosin, a secondary metabolite produced by Serratia marcescens, has attracted attention due to its immunosuppressive, antimicrobial, and anticancer properties. However, information on the regulatory mechanism behind prodigiosin biosynthesis in S. marcescens remains limited. In this work, a prodigiosin-hyperproducing strain with the BVG90_22495 gene disrupted (ZK66) was selected from a collection of Tn5G transposon insertion mutants. Using real-time quantitative PCR (RT-qPCR) analysis, β-galactosidase assays, transcriptomics analysis, and electrophoretic mobility shift assays (EMSAs), the LysR-type regulator MetR encoded by the BVG90_22495 gene was found to affect prodigiosin synthesis, and this correlated with MetR directly binding to the promoter region of the prodigiosin-synthesis positive regulator PigP and hence negatively regulated the expression of the prodigiosin-associated pig operon. More analyses revealed that MetR regulated some other important cellular processes, including methionine biosynthesis, cell motility, H2O2 tolerance, heat tolerance, exopolysaccharide synthesis, and biofilm formation in S. marcescens. Although MetR protein is highly conserved in many bacteria, we report here on the LysR-type regulator MetR exhibiting novel roles in negatively regulating prodigiosin synthesis and positively regulating heat tolerance, exopolysaccharide synthesis, and biofilm formation. IMPORTANCE Serratia marcescens, a Gram-negative bacterium, is found in a wide range of ecological niches and can produce several secondary metabolites, including prodigiosin, althiomycin, and serratamolide. Among them, prodigiosin shows diverse functions as an immunosuppressant, antimicrobial, and anticancer agent. However, the regulatory mechanisms behind prodigiosin synthesis in S. marcescens are not completely understood. Here, we adapted a transposon mutant library to identify the genes related to prodigiosin synthesis, and the BVG90_22495 gene encoding the LysR-type regulator MetR was found to negatively regulate prodigiosin synthesis. The molecular mechanism of the metR mutant hyperproducing prodigiosin was investigated. Additionally, we provided evidence supporting new roles for MetR in regulating methionine biosynthesis, cell motility, heat tolerance, H2O2 tolerance, and exopolysaccharide synthesis in S. marcescens. Collectively, this work provides novel insight into regulatory mechanisms of prodigiosin synthesis and uncovers novel roles for the highly conserved MetR protein in regulating prodigiosin synthesis, heat tolerance, exopolysaccharide (EPS) synthesis, and biofilm formation. ? 2020 American Society for Microbiology. All Rights Reserved.