文献类型：期刊文献

英文题名：LcbR1, a newly identified GntR family regulator, represses lincomycin biosynthesis in Streptomyces lincolnensis

作者：Wang, Ruida[1,2];Zhao, Jiaqi[1,2];Chen, Lei[1,2];Ye, Jiang[1,2];Wu, Haizhen[1,2];Zhang, Huizhan[1,2]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Biotechnol, Dept Appl Biol, Shanghai 200237, Peoples R China

年份：2023

卷号：107

期号：24

起止页码：7501

外文期刊名：APPLIED MICROBIOLOGY AND BIOTECHNOLOGY

收录：;EI(收录号：20234014835820);WOS:【SCI-EXPANDED(收录号:WOS:001074762500001)】；

基金：We thank Prof. Yihua Chen from the Institute of Microbiology for kindly providing the idgS-containing plasmid pCIMt02 and Wenli Jiang from our laboratory for assistance in EMSA experiments.

语种：英文

外文关键词：Streptomyces lincolnensis; LcbR1; GntR family; Lincomycin biosynthesis; Transcriptional regulation

摘要：The Actinomycetes Streptomyces lincolnensis is the producer of lincosamide-type antibiotic lincomycin, a widely utilized drug against Gram-positive bacteria and protozoans. In this work, through gene knockout, complementation, and overexpression experiments, we identified LcbR1 (SLINC_1595), a GntR family transcriptional regulator, as a repressor for lincomycin biosynthesis. Deletion of lcbR1 boosted lincomycin production by 3.8-fold, without obvious change in morphological development or cellular growth. The homologues of LcbR1 are widely distributed in Streptomyces. Heterologous expression of SCO1410 from Streptomyces coelicolor resulted in the reduction of lincomycin yield, implying that the function of LcbR1 is conserved across different species. Alignment among sequences upstream of lcbR1 and their homologues revealed a conserved 16-bp palindrome (-TTGAACGATCCTTCAA-), which was further proven to be the recognition motif of LcbR1 by electrophoretic mobility shift assays (EMSAs). Via this motif, LcbR1 suppressed the transcription of lcbR1 and SLINC_1596 sharing the same bi-directional promoter. SLINC_1596, one important target of LcbR1, exerted a positive effect on lincomycin production. As detected by quantitative real-time PCR (qRT-PCR) analyses, the expressions of all selected structural (lmbA, lmbC, lmbJ, lmbV, and lmbW), resistance (lmrA and lmrB) and regulatory genes (lmrC and lmbU) from lincomycin biosynthesis cluster were upregulated in deletion strain Delta lcbR1 at 48 h of fermentation, while the mRNA amounts of bldD, glnR, ramR, SLCG_Lrp, and SLCG_2919, previously characterized as the regulators on lincomycin production, were decreased in strain Delta lcbR1, although the regulatory effects of LcbR1 on the above differential expression genes seemed to be indirect. Besides, indicated by EMSAs, the expression of lcbR1 might be regulated by GlnR, SLCG_Lrp, and SLCG_2919, which shows the complexity of the regulatory network on lincomycin biosynthesis.