Gene

Biology

Peptide

Cyclic peptide

Enterprise architecture

Peptide Biosynthesis

Biochemistry

Visual arts

Enterprise architecture management

Architecture

Stereochemistry

Architecture domain

Biosynthesis

Enzyme

Chemistry

Ribosome

Nature Chemical Biology

Many bioactive plant cyclic peptides form side-chain-derived macrocycles. Lyciumins, cyclic plant peptides with tryptophan macrocyclizations, are ribosomal peptides (RiPPs) originating from repetitive core peptide motifs in precursor peptides with plant-specific BURP (BNM2, USP, RD22 and PG1beta) domains, but the biosynthetic mechanism for their formation has remained unknown. Here, we characterize precursor-peptide BURP domains as copper-dependent autocatalytic peptide cyclases and use a combination of tandem mass spectrometry-based metabolomics and plant genomics to systematically discover five BURP-domain-derived plant RiPP classes, with mono- and bicyclic structures formed via tryptophans and tyrosines, from botanical collections. As BURP-domain cyclases are scaffold-generating enzymes in plant specialized metabolism that are physically connected to their substrates in the same polypeptide, we introduce a bioinformatic method to mine plant genomes for precursor-peptide-encoding genes by detection of repetitive substrate domains and known core peptide features. Our study sets the stage for chemical, biosynthetic and biological exploration of plant RiPP natural products from BURP-domain cyclases.                                                                  BURP domains within lyciumin precursor peptides serve as autocatalytic peptide cyclases, enabling the discovery of other BURP-domain-derived products and development of a bioinformatic method to mine plants for precursor-peptide-encoding genes.

Discovery and biosynthesis of cyclic plant peptides via autocatalytic cyclases