The Final Steps in Pseudoiodinine Biosynthesis Feature Ring-Contractive N-N Bond Formation.

ABSTRACT: Pseudoiodinine (PSD) is a N-N bond-containing natural product with profound antimicrobial and antifungal activities. In this work, we have completed the PSD biosynthetic pathway by explicating the final three steps, which involve an enigmatic N-N bond formation in a ring contraction process. As a starting material, 1,6-didesmethyltoxoflavin (1,6-DDMT) is sequentially methylated by PsdF and PsdA to give 5-methoxy-6-desmethyltoxoflavin (5-OCH₃-6-DMT), which then undergoes oxidative decarboxylation for the ring-contractive N-N bond formation to generate the pyrazole ring catalyzed by PsdB, a novel vicinal oxygen chelate superfamily (VOC) protein. This is the first enzyme in the VOC family to catalyze such a reaction, providing new insight into N-N bond formation.

SUBMITTER: Zhu L 

PROVIDER: S-EPMC12308417 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature