P450 cyptide synthase MpoB catalyzes the cross-linking of the YPW motif on the precursor peptide.

Cytochrome P450 enzymes in ribosomally synthesized and post-translationally modified peptides (RiPPs) catalyze C-C, C-N, or C-O cross-linking reactions in the biosynthesis of biaryl cyclophane natural products. Here, we manually identified 127 homologous P450s linked to putative precursor peptides containing the YPW motif. Through in vivo functional studies in Escherichia coli, the newly identified enzyme MpoB from Micromonospora polyrhachis DSM 45886 was found to catalyze the formation of a cross-link between Tyr-C3 and Trp-N1 at the YPW motif. This result provides an additional toolkit for cross-linked peptide modification.