文献类型：期刊文献

英文题名：LmbU, a Cluster-Situated Regulator for Lincomycin, Consists of a DNA-Binding Domain, an Auto-Inhibitory Domain, and Forms Homodimer

作者：Hou, Bingbing[1];Zhu, Xiaoyu[1];Kang, Yajing[1];Wang, Ruida[1];Wu, Haizhen[1,2];Ye, Jiang[1,2];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

年份：2019

卷号：10

外文期刊名：FRONTIERS IN MICROBIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000467027300001)】；

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; CSR; functional domain; HTH; homodimer; regulatory mechanism

摘要：Few studies were reported about the regulatory mechanism of lincomycin biosynthesis since it was found in 1962. Although we have proved that a cluster-situated regulator (CSR) LmbU (GenBank Accession No. ABX00623.1) positively modulates lincomycin biosynthesis in Streptomyces lincolnensis NRRL 2936, the molecular mechanism of LmbU regulation is still unclear. In this study, we demonstrated that LmbU binds to the target lmbAp by a central DNA-binding domain (DBD), which interacts with the binding sites through the helix-turn-helix (HTH) motif. N-terminal of LmbU includes an auto-inhibitory domain (AID), inhibiting the DNA-binding activity of LmbU. Without the AID, LmbU variant can bind to its own promoter. Interestingly, compared to other LmbU homologs, the homologs within the biosynthetic gene clusters (BGCs) of known antibiotics generally contain N-terminal AIDs, which offer them the abilities to play complex regulatory functions. In addition, cysteine 12 (C12) has been proved to be mainly responsible for LmbU homodimer formation in vitro. In conclusion, LmbU homologs naturally exist in hundreds of actinomycetes, and belong to a new regulatory family, LmbU family. The present study reveals the DBD, AID and dimerization of LmbU, and sheds new light on the regulatory mechanism of LrnbU and its homologs.