文献类型：期刊文献

英文题名：Enhanced lincomycin production by co-overexpression of metK1 and metK2 in Streptomyces lincolnensis

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

机构：[1]Anhui Univ, Inst Phys Sci & Informat Technol, Sch Chem & Chem Engn, Sch Life Sci, Hefei 230601, Anhui, Peoples R China;[2]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[3]Shanghai Jiao Tong Univ, State Key Lab Microbial Metab, Shanghai 200240, Peoples R China;[4]Xinyu Pharmaceut Co Ltd, Suzhou 234000, Peoples R China

年份：2018

卷号：45

期号：5

起止页码：345

外文期刊名：JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY

收录：;EI(收录号：20242616426725);WOS:【SCI-EXPANDED(收录号:WOS:000430547000006)】；

基金：We are grateful to Dr. Sabrina Huber from Department of Biological Engineering at Massachusetts Institute of Technology for critical editing of the manuscript. This work was supported by the National Natural Science Foundation of China (31300081, 31570074, 31600064), the National Program on Key Basic Research Project (973 programs, 2013CB734000), Open Project of State Key Laboratory of Microbial Metabolism from Shanghai Jiao Tong University (MMLKF13-05), the Initial Foundation of Doctoral Scientific Research in Anhui University (01001904, J01001935), and the National Innovation Experiment Program for University Students (J10118516053).

语种：英文

外文关键词：Streptomyces lincolnensis; Lincomycin; S-adenosylmethionine (SAM); SAM synthetase

摘要：Streptomyces lincolnensis is generally utilized for the production of lincomycin A (Lin-A), a clinically useful antibiotic to treat Gram-positive bacterial infections. Three methylation steps, catalyzed by three different S-adenosylmethionine (SAM)-dependent methyltransferases, are required in the biosynthesis of Lin-A, and thus highlight the significance of methyl group supply in lincomycin production. In this study, we demonstrate that externally supplemented SAM cannot be taken in by cells and therefore does not enhance Lin-A production. Furthermore, bioinformatics and in vitro enzymatic assays revealed there exist two SAM synthetase homologs, MetK1 (SLCG_1651) and MetK2 (SLCG_3830) in S. lincolnensis that could convert l-methionine into SAM in the presence of ATP. Even though we attempted to inactivate metK1 and metK2, only metK2 was deleted in S. lincolnensis LCGL, named as Delta metK2. Following a reduction of the intracellular SAM concentration, Delta metK2 mutant exhibited a significant decrease of Lin-A in comparison to its parental strain. Individual overexpression of metK1 or metK2 in S. lincolnensis LCGL either elevated the amount of intracellular SAM, concomitant with 15% and 22% increase in Lin-A production, respectively. qRT-PCR assays showed that overexpression of either metK1 or metK2 increased the transcription of lincomycin biosynthetic genes lmbA and lmbR, and regulatory gene lmbU, indicating SAM may also function as a transcriptional activator. When metK1 and metK2 were co-expressed, Lin-A production was increased by 27% in LCGL, while by 17% in a high-yield strain LA219X.