The l ‐Alanosine Gene Cluster Encodes a Pathway for Diazeniumdiolate Biosynthesis

Autor: Christine R. Zheng, Tai L. Ng, Kelvin J. Y. Wu, Monica E. McCallum, Jennifer X. Wang, Emily P. Balskus
Rok vydání: 2019
Předmět:
Zdroj: Chembiochem
ISSN: 1439-7633
1439-4227
DOI: 10.1002/cbic.201900565
Popis: N-Nitroso-containing natural products are bioactive metabolites with antibacterial and anticancer properties. In particular, compounds containing the diazeniumdiolate (N-nitrosohydroxylamine) group display a wide range of bioactivities ranging from cytotoxicity to metal chelation. Despite the importance of this structural motif, knowledge of its biosynthesis is limited. Herein we describe the discovery of a biosynthetic gene cluster in Streptomyces alanosinicus ATCC 15710 responsible for producing the diazeniumdiolate natural product l-alanosine. Gene disruption and stable isotope feeding experiments identified essential biosynthetic genes and revealed the source of the N-nitroso group. Additional biochemical characterization of the biosynthetic enzymes revealed that the non-proteinogenic amino acid l-2,3-diaminopropionic acid (l-Dap) is synthesized and loaded onto a free-standing peptidyl carrier protein (PCP) domain in l-alanosine biosynthesis, which we propose may be a mechanism of handling unstable intermediates generated en route to the diazeniumdiolate. These discoveries will facilitate efforts to determine the biochemistry of diazeniumdiolate formation.
Databáze: OpenAIRE