Characterization of a novel regulatory pathway for mannitol metabolism and its coordination with biofilm formation in Mycobacterium smegmatis

作     者：Jialing Hu Hua Zhang Si Zhou Weihui Li Zheng-Guo He 

作者机构：National Key Laboratory of Agricultural MicrobiologyCollege of Life Science and TechnologyHuazhong Agricultural University 

出 版 物：《Journal of Genetics and Genomics》 (遗传学报（英文版）)

年 卷 期：2018年第45卷第9期

页      面：477-488页

核心收录：

学科分类：0710[理学-生物学] 07[理学] 1001[医学-基础医学(可授医学、理学学位)] 071007[理学-遗传学] 

基　　金：supported by the National Key R&D Program of China (2017YFD0500300) the National Natural Science Foundation of China (Nos.31730005,31401108,and 31670075) the Fundamental Research Funds for the Central Universities (2662016PY090) Chang Jiang Scholars Program (to Z.-G. He) 

主　　题：Transcription regulation Biofilm formation Mannitol Mycobacteria 

摘      要：Biofilm formation has been implicated to be tightly regulated in bacteria. Mycobacterial species possess a unique cell-wall structure; however, the underlying regulation mechanism for their biofilm formation remains largely unclear. In this study, we characterized a hypothetical mannitol metabolism and transportation gene cluster（Ms5571-Ms5576）, designated as mmt operon, whose expression significantly contributes to the biofilm formation in Mycobacterium smegmatis. We showed that in the operon the Ms5575 gene encodes a GntR-like transcriptional repressor and the Ms5576 gene encodes a mannitol2-dehydrogenase which can produce D-mannitol from D-mannose. Strikingly, the D-mannitol molecule can derepress the negative regulation of Ms5575 on the mmt operon to stimulate the operon＇s expression. Consistently, addition of D-mannitol into the medium can obviously induce mycobacterial biofilm formation. Furthermore, we found that Ms0179 positively regulates the mmt operon through its downstream regulator Ms0180. Ms0180 directly binds the mmt operon to positively regulate its expression. Both Ms0179 and Ms0180 significantly affect the mycobacterial biofilm formation. Taken together, we explored a regulatory pathway for the mannitol metabolism and its coordination with the biofilm formation in M. smegmatis. This finding provides novel insights into the unique mechanism of biofilm formation regulation in mycobacteria.