Bacteria synthesize a bacteriocin within the cell membrane.

Bacteria synthesize a membrane-integrated bacteriocin, TMcin, within the cell membrane, revealing a novel pathway for RiPP biosynthesis.

• Why it matters: Understanding bacterial production of antimicrobials is crucial for developing new antibiotics and comprehending microbial community dynamics, especially since TMcins challenge the traditional soluble peptide paradigm.
• What they did: Using an inducible biosynthesis system guided by structure prediction, the study shows that the precursor peptide TmcA is integrated into the bacterial membrane and is modified there, with three of four biosynthetic steps mediated by intramembrane proteins.
• The result: The findings establish a membrane-localized RiPP biosynthesis pathway, highlight an essential escort protein in TMcin maturation, and suggest that bacteria can produce peptide natural products directly from within the cell membrane.