title: TmcN is involved in ATP regulation of tautomycetin biosynthesis in Streptomyces griseochromogenes.
abstract: The regulatory mechanism of tautomycetin (TMC) biosynthesis remains largely unknown, although it has been of great interest to the pharmaceutical industry. Our previous study showed that intracellular adenosine triphosphate (inATP) level is negatively correlated with secondary metabolite biosynthesis in various Streptomyces spp. In this study, by exogenous treatment of ATP, we also found a negative correlation between TMC biosynthesis and inATP level in Streptomyces griseochromogenes (S. griseochromogenes). However, the underlying mechanism remains unclear. TmcN, a pathway-specific transcriptional regulator of TMC biosynthetic genes, was previously revealed as a large ATP-binding LuxR (LAL) family protein. The predicted amino acid sequence of TmcN shows highly conserved Walker A and B binding motifs, which suggest an ATPase function of TmcN. We therefore hypothesized that the ATPase domain of TmcN may play a role in sensing endogenous pool of ATP, and is thus involved in the ATP regulation of TMC biosynthesis. To test the hypothesis, we first explored the key residue that affects the ATPase activity of TmcN by amino acid sequence alignment and structural simulation. After that, we disrupted tmcN gene in S. griseochromogenes, and the tmcN or site-direct-mutated tmcN were re-introduced to get the complementary and ATPase domain disrupted strains. The transcription level of tmcN, TMC yield, and inATP, as well as the effect of ATP on TMC production of different mutants were evaluated. Deletion of tmcN or site-direct mutation of ATPase domain of TmcN in S. griseochromogenes significantly reduced the TMC production, and it was not affected by exogenous ATP treatment. In addition, a relatively high level of inATP was detected in tmcN deletion and site-direct mutation strains. Our results here suggested that TmcN, especially its ATPase domain, is involved in consuming of endogenous ATP pool and thus plays pivotal role in connecting the primary and secondary metabolite in S. griseochromogenes.
authors.affiliation: Department of Microecology, College of Basic Medical Science, Dalian Medical University, Dalian, Liaoning 116044, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Biotechnology, College of Basic Medical Science, Dalian Medical University, Dalian, Liaoning 116044, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Research Center for Molecular Medicine, Dalian University of Technology, Dalian, Liaoning 116023, China.
authors.forename: Sijin
authors.initials: S
authors.lastname: Wu
authors.affiliation: Department of Microecology, College of Basic Medical Science, Dalian Medical University, Dalian, Liaoning 116044, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Microecology, College of Basic Medical Science, Dalian Medical University, Dalian, Liaoning 116044, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Department of Microecology, College of Basic Medical Science, Dalian Medical University, Dalian, Liaoning 116044, China.
authors.forename: Jieli
authors.initials: J
authors.lastname: Yuan
authors.affiliation: Laboratory Animal Center, Dalian Medical University, Dalian, Liaoning 116044, China. Electronic address: beedream@126.com.
authors.forename: Jianyi
authors.initials: J
authors.lastname: Dong
authors.affiliation: Department of Microecology, College of Basic Medical Science, Dalian Medical University, Dalian, Liaoning 116044, China. Electronic address: lhjcmu@hotmail.com.
authors.forename: Huajun
authors.initials: H
authors.lastname: Li
authors.affiliation: Research Center for Molecular Medicine, Dalian University of Technology, Dalian, Liaoning 116023, China. Electronic address: tangli63b@yahoo.com.
authors.forename: Li
authors.initials: L
authors.lastname: Tang
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D005663:Furans; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D008055:Lipids / Q000096:biosynthesis*; D013305:Streptomyces griseus / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D005663:Furans; D008055:Lipids; D014157:Transcription Factors; C058744:tautomycetin; D000255:Adenosine Triphosphate
keywords: ATP; ATPase; Streptomyces griseochromogenes; Tautomycetin; TmcN