文献类型：期刊文献

英文题名：The Novel Transcriptional Regulator LmbU Promotes Lincomycin Biosynthesis through Regulating Expression of Its Target Genes in Streptomyces lincolnensis

作者：Hou, Bingbing[1];Lin, Yanwei[1];Wu, Haizhen[1,2];Guo, Meijin[1];Petkovic, Hrvoje[3];Tao, Liyuan[1];Zhu, Xiaoyu[1];Ye, Jiang[1];Zhang, Huizhan[1,2]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai, Peoples R China;[2]East China Univ Sci & Technol, Dept Appl Biol, Shanghai, Peoples R China;[3]Univ Ljubljana, Biotech Fac, Ljubljana, Slovenia

年份：2018

卷号：200

期号：2

外文期刊名：JOURNAL OF BACTERIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000418349800005)】；

基金：This study was supported by the National Natural Science Foundation of China (NSFC) (3120026).

语种：英文

外文关键词：LmbU; LmbU homologues; Streptomyces; cluster-situated regulator; lincomycin; regulatory protein

摘要：Lincomycin A is a clinically important antimicrobial agent produced by Streptomyces lincolnensis. In this study, a new regulator designated LmbU (GenBank accession no. ABX00623.1) was identified and characterized to regulate lincomycin biosynthesis in S. lincolnensis wild-type strain NRRL 2936. Both inactivation and overexpression of lmbU resulted in significant influences on lincomycin production. Transcriptional analysis and in vivo neomycin resistance (Neo(r)) reporter assays demonstrated that LmbU activates expression of the lmbA, lmbC, lmbJ, and lmbW genes and represses expression of the lmbK and lmbU genes. Electrophoretic mobility shift assays (EMSAs) demonstrated that LmbU can bind to the regions upstream of the lmbA and lmbW genes through the consensus and palindromic sequence 5'-CGCCG GCG-3'. However, LmbU cannot bind to the regions upstream of the lmbC, lmbJ, lmbK, and lmbU genes as they lack this motif. These data indicate a complex transcriptional regulatory mechanism of LmbU. LmbU homologues are present in the biosynthetic gene clusters of secondary metabolites of many other actinomycetes. Furthermore, the LmbU homologue from Saccharopolyspora erythraea (GenBank accession no. WP_009944629.1) also binds to the regions upstream of lmbA and lmbW, which suggests widespread activity for this regulator. LmbU homologues have no significant structural similarities to other known cluster-situated regulators (CSRs), which indicates that they belong to a new family of regulatory proteins. In conclusion, the present report identifies LmbU as a novel transcriptional regulator and provides new insights into regulation of lincomycin biosynthesis in S. lincolnensis. IMPORTANCE Although lincomycin biosynthesis has been extensively studied, its regulatory mechanism remains elusive. Here, a novel regulator, LmbU, which regulates transcription of its target genes in the lincomycin biosynthetic gene cluster (lmb gene cluster) and therefore promotes lincomycin biosynthesis, was identified in S. lincolnensis strain NRRL 2936. Importantly, we show that this new regulatory element is relatively widespread across diverse actinomycetes species. In addition, our findings provide a new strategy for improvement of yield of lincomycin through manipulation of LmbU, and this approach could also be evaluated in other secondary metabolite gene clusters containing this regulatory protein.