1. Academic Validation
  2. Actinobacterial chalkophores: the biosynthesis of hazimycins

Actinobacterial chalkophores: the biosynthesis of hazimycins

  • J Antibiot (Tokyo). 2024 Apr;77(4):228-237. doi: 10.1038/s41429-024-00706-6.
Kenichi Matsuda 1 Hiroto Maruyama 2 Kumiko Imachi 2 Haruo Ikeda 3 Toshiyuki Wakimoto 4
Affiliations

Affiliations

  • 1 Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan. kematsuda@pharm.hokudai.ac.jp.
  • 2 Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan.
  • 3 Technology Research Association for Next generation natural products chemistry, 2-4-7 Aomi, Koto-ku, Tokyo, 135-0064, Japan.
  • 4 Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan. wakimoto@pharm.hokudai.ac.jp.
Abstract

Copper is a transition metal element with significant effects on the morphological development and secondary metabolism of actinobacteria. In some Microorganisms, copper-binding Natural Products are employed to modulate copper homeostasis, although their significance in actinobacteria remains largely unknown. Here, we identified the biosynthetic genes of the diisocyanide natural product hazimycin in Kitasatospora purpeofusca HV058, through gene knock-out and heterologous expression. Biochemical analyses revealed that hazimycin A specifically binds to copper, which diminishes its antimicrobial activity. The presence of a set of putative importer/exporter genes surrounding the biosynthetic genes suggested that hazimycin is a chalkophore that modulates the intracellular copper level. A bioinformatic survey of homologous gene cassettes, as well as the identification of two previously unknown hazimycin-producing Streptomyces strains, indicated that the isocyanide-based mechanism of copper homeostasis is prevalent in actinobacteria.

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