H-NS family protein MvaU downregulates phenazine-1-carboxylic acid(PCA)biosynthesis via binding to an AT-rich region within the promoter of the phz2 gene cluster in the rhizobacterium Pseudomonas strain PA1201  

作　　者：Yun-Ling Fang Ying Cui Lian Zhou Chitti Thawai Tatheer Alam Naqvi Hong-Yan Zhang Ya-Wen He 

机构地区：[1]State Key Laboratory of Microbial Metabolism,Joint International Research Laboratory of Metabolic and Developmental Sciences,SJTU-Shanghai Nong Le Joint R&D Center on Biopesticides and Biofertilizers,Shanghai Jiao Tong University(SJTU),Shanghai,200240,China [2]Department of Biology,Faculty of Science,King Mongkut’s Institute of Technology Ladkrabang,Bangkok,Thailand [3]Department of Biotechnology,COMSATS University Islamabad,Abbottabad Campus,Abbottabad,Pakistan [4]Shanghai Nong Le Biological Products Company Limited,Shanghai,201419,China

出　　处：《Synthetic and Systems Biotechnology》2021年第4期262-271,共10页合成和系统生物技术（英文）

基　　金：This work was financially supported by grants from National Key R&D Program of China(2018YFA0901901 to Y.-W.He);National Natural Science Foundation of China(No.31972231 to Y.-W.He).

摘　　要：Histone-like nucleoid-structuring(H-NS)proteins are key regulators in gene expression silencing and in nucleoid compaction.The H-NS family member proteins MvaU in Pseudomonas aeruginosa are thought to bind the same AT-rich regions of chromosomes and function to coordinate the control of a common set of genes.Here,we explored the molecular mechanism by which MvaU controls PCA biosynthesis in P.aeruginosa PA1201.We present evidence suggesting that MvaU is self-regulated.Deletion of mvaU significantly increased PCA production,and PCA production sharply decreased when mvaU was over-expressed.MvaU transcriptionally repressed phz2 cluster expression and consequently reduced PCA biosynthesis.β-galactosidase assays confirmed that base pairing near the35 box is required when MvaU regulates PCA production in PA1201.Electrophoretic mobility shift assays(EMSA)and additional point mutation analysis demonstrated that MvaU directly bound to an AT-rich motif within the promoter of the phz2 cluster.Chromatin immunoprecipitation(ChIP)analysis also indicated that MvaU directly bound to the P5 region of the phz2 cluster promoter.MvaU repression of PCA biosynthesis was independent of QscR and OxyR in PA1201 and neither PCA or H2O2 were the environmental signals that induced mvaU expression.These findings detail a new MvaU-dependent regulatory pathway of PCA biosynthesis in PA1201 and provide a foundation to increase PCA fermentation titer by genetic engineering.

关 键 词：PSEUDOMONAS Phenazine-1-carboxylic acid phz cluster MvaU Regulatory network 

分 类 号：Q93[生物学—微生物学]