Oxidative Peptide Backbone Cleavage by a HEXXH Enzyme During RiPP Biosynthesis.

ABSTRACT: Ribosomally synthesized and post-translationally modified peptides (RiPPs) rely on a diverse array of enzymes to tailor peptide backbones and side chains. In this study, we characterized enzymes from two different biosynthetic gene clusters (BGCs) from Pseudomonas strains (pfl and pos) that catalyze new transformations in RiPP biosynthesis. Two α-ketoglutarate-dependent HEXXH enzymes, PflC and PosC, perform hydroxylation of multiple consecutive glutamine residues and selectively recognize a C-terminal ARMD tetrapeptide to trigger oxidative backbone cleavage that generates an amide terminus. Mutational analysis pinpoints the first position of this motif as a critical determinant. Notably, PflC displays proteolytic activity in the absence of the leader peptide, indicating that

SUBMITTER: Ouyang Y 

PROVIDER: S-EPMC12636437 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature