Bottromycin D is a ribosomally synthesized and post-translationally modified peptide (RiPP) that displays antibiotic activity against methicillin-resistant S.aureus (MRSA). The precursor peptide is first ribosomally synthesized and then highly tailored by specific enzymes to yield the final natural product. These modifications include several methylations, cyclization and the formation of t-Leu and Thia-beta-Ala residues.