Predicted structure for Mbn from Ms. sp. LW4 (top) along with its Mbn operon (middle) and MbnA sequence (bottom, leader peptide in gray and core peptide in black). Biosynthesis genes encode the precursor peptide (MbnA), the uncharacterized proteins MbnB and MbnC, and the aminotransferase MbnN. Other genes are related to regulation (MbnI, MbnR) or transport (MbnT, MbnM).