title: Discovery and engineered overproduction of antimicrobial nucleoside antibiotic A201A from the deep-sea marine actinomycete Marinactinospora thermotolerans SCSIO 00652.
abstract: Marinactinospora thermotolerans SCSIO 00652, originating from a deep-sea marine sediment of the South China Sea, was discovered to produce antimicrobial nucleoside antibiotic A201A. Whole-genome scanning and annotation strategies enabled us to localize the genes responsible for A201A biosynthesis and to experimentally identify the gene cluster; inactivation of mtdF, an oxidoreductase gene within the suspected gene cluster, abolished A201A production. Bioinformatics analysis revealed that a gene designated mtdA furthest upstream within the A201A biosynthetic gene cluster encodes a GntR family transcriptional regulator. To determine the role of MtdA in regulating A201A production, the mtdA gene was inactivated in frame and the resulting ΔmtdA mutant was fermented alongside the wild-type strain as a control. High-performance liquid chromatography (HPLC) analyses of fermentation extracts revealed that the ΔmtdA mutant produced A201A in a yield ∼25-fold superior to that of the wild-type strain, thereby demonstrating that MtdA is a negative transcriptional regulator governing A201A biosynthesis. By virtue of its high production capacity, the ΔmtdA mutant constitutes an ideal host for the efficient large-scale production of A201A. These results validate M. thermotolerans as an emerging source of antibacterial agents and highlight the efficiency of metabolic engineering for antibiotic titer improvement.
authors: CAS Key Laboratory of Marine Bio-resources Sustainable Utilization, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
authors: Qinghua
authors: Q
authors: Zhu
authors: Jun
authors: J
authors: Li
authors: Junying
authors: J
authors: Ma
authors: Minghe
authors: M
authors: Luo
authors: Bo
authors: B
authors: Wang
authors: Hongbo
authors: H
authors: Huang
authors: Xinpeng
authors: X
authors: Tian
authors: Wenjun
authors: W
authors: Li
authors: Si
authors: S
authors: Zhang
authors: Changsheng
authors: C
authors: Zhang
authors: Jianhua
authors: J
authors: Ju
mesh_terms: D000192:Actinomycetales / Q000201:enzymology / Q000235:genetics*; D000595:Amino Acid Sequence; D000617:Aminoglycosides / Q000096:biosynthesis; D000900:Anti-Bacterial Agents / Q000096:biosynthesis; D059001:Aquatic Organisms; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002681:China; D002851:Chromatography, High Pressure Liquid; D019295:Computational Biology; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial; D055106:Genome-Wide Association Study; D015698:Genomic Library; D007218:Industrial Microbiology; D060847:Metabolic Engineering; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D009792:Oceans and Seas; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C046076:A 201A; D010088:Oxidoreductases