文献类型：期刊文献

英文题名：TetR-Type Regulator SLCG_2919 Is a Negative Regulator of Lincomycin Biosynthesis in Streptomyces lincolnensis

作者：Xu, Yurong[1,2];Ke, Meilan[1];Li, Jie[1];Tang, Yaqian[1];Wang, Nian[1];Tan, Guoqing[1];Wang, Yansheng[1];Liu, Ruihua[5];Bai, Linquan[4];Zhang, Lixin[1,3];Wu, Hang[1];Zhang, Buchang[1]

机构：[1]Anhui Univ, Inst Phys Sci & Informat Technol, Sch Chem & Chem Engn, Sch Life Sci, Hefei, Anhui, Peoples R China;[2]Hefei Normal Univ, Dept Chem & Chem Engn, Hefei, Anhui, Peoples R China;[3]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai, Peoples R China;[4]Shanghai Jiao Tong Univ, State Key Lab Microbial Metab, Shanghai, Peoples R China;[5]Xinyu Pharmaceut Co Ltd, Suzhou, Peoples R China

年份：2019

卷号：85

期号：1

外文期刊名：APPLIED AND ENVIRONMENTAL MICROBIOLOGY

收录：;EI(收录号：20190206368997);WOS:【SCI-EXPANDED(收录号:WOS:000452985900013)】；

基金：This work was supported by the National Natural Science Foundation of China (grants 31300081, 31570074, and 31600064), the Open Project of State Key Laboratory of Microbial Metabolism from Shanghai Jiao Tong University (grant MMLKF13-05), the Open Fund for Discipline Construction from Institute of Physical Science and Information Technology at Anhui University, and the Anhui Provincial Natural Science Foundation (grant 1708085QC49).

语种：英文

外文关键词：lincomycin; SLCG_2919; Streptomyces lincolnensis; TetR family transcriptional regulator

摘要：Lincomycin A (Lin-A) is a widely used antibacterial antibiotic fermented by Streptomyces lincolnensis. However, the transcriptional regulatory mechanisms underlying lincomycin biosynthesis have seldom been investigated. Here, we first identified a TetR family transcriptional regulator (TFR), SLCG_2919, which negatively modulates lincomycin biosynthesis in S. lincolnensis LCGL. SLCG_2919 was found to specifically bind to promoter regions of the lincomycin biosynthetic gene cluster (lin cluster), including 25 structural genes, three resistance genes, and one regulatory gene, and to inhibit the transcription of these genes, demonstrating a directly regulatory role in lincomycin biosynthesis. Furthermore, we found that SLCG_2919 was not autoregulated, but directly repressed its adjacent gene, SLCG_2920, which encodes an ATP/GTP binding protein whose overexpression increased resistance against lincomycin and Lin-A yields in S. lincolnensis. The precise SLCG_2919 binding site within the promoter region of SLCG_2920 was determined by a DNase I foot-printing assay and by electrophoretic mobility shift assays (EMSAs) based on base substitution mutagenesis, with the internal 10-nucleotide (nt) AT-rich sequence (AAATTATTTA) shown to be essential for SLCG_2919 binding. Our findings indicate that SLCG_2919 is a negative regulator for controlling lincomycin biosynthesis in S. lincolnensis. The present study improves our understanding of molecular regulation for lincomycin biosynthesis. IMPORTANCE TetR family transcriptional regulators (TFRs) are generally found to regulate diverse cellular processes in bacteria, especially antibiotic biosynthesis in Streptomyces species. However, knowledge of their function in lincomycin biosynthesis in S. lincolnensis remains unknown. The present study provides a new insight into the regulation of lincomycin biosynthesis through a TFR, SLCG_2919, that directly modulates lincomycin production and resistance. Intriguingly, SLCG_2919 and its adjoining gene, SLCG 2920, which encodes an ATP/GTP binding protein, were extensively distributed in diverse Streptomyces species. In addition, we revealed a new TFR binding motif, in which SLCG_2919 binds to the promoter region of SLCG_2920, dependent on the intervening AT-rich sequence rather than on the flanking inverted repeats found in the binding sites of other TFRs. These insights into transcriptional regulation of lincomycin biosynthesis by SLCG_2919 will be valuable in paving the way for genetic engineering of regulatory elements in Streptomyces species to improve antibiotic production.