Serine proteases in ribosomally synthesized and post-translationally modified peptides (RiPPs) catalyze the cleavage on the precursor peptides in the biosynthesis of RiPP natural products. Here, we identified an uncharacterized serine protease WprP2 from Streptomyces venezuelae NPDC049867, encoded next to the radical S-adenosyl-L-methionine (SAM) enzyme WprB2 involved in the biosynthesis of cyclophane natural products. In vitro characterization of S9 protease WprP2 revealed that the precursor peptide WprA2 is uniformly cleaved. The cleavage activity of WprP2 has not been seen in any serine proteases and expands the S9 protease in RiPP biosynthesis.
Haedar et al. (Thu,) studied this question.