An Unusual Ring Pattern in the Rosβ Lanthipeptide of the Two-Component Lantibiotic Roseocin
Year: 2026
Type: article
Abstract: Two-component lantibiotics comprise two post-translationally modified peptides that synergistically exert antimicrobial activity. Most known two-component lantibiotics are made up of a structurally conserved α-lanthipeptide that binds to the peptidoglycan precursor lipid II and a β-lanthipeptide that is believed to interact with the α-peptide-lipid II complex to form pores in the membranes of susceptible bacteria. A few two-component lantibiotics including roseocin do not follow this general scheme and act by different, currently unresolved mechanisms. An important first step in studying this group of lanthipeptides is determination of their chemical structure. Roseocin’s β-peptide (Rosβ) is formed by the RosM lanthipeptide synthetase from the RosA1 precursor peptide. RosM carries out nine dehydrations of Ser and Thr residues to the corresponding dehydroamino acids followed by six Michael-type additions of the thiols of Cys residues to a subset of the dehydroamino acids forming six thioether crosslinks. Sequence alignment with structurally characterized lanthipeptides does not allow prediction of its ring pattern. In this study, Rosβ was produced in Escherichia coli and its ring pattern was established by multi-dimensional NMR spectroscopy. The stereochemistry of the lanthionine and methyllanthionine residues was determined by Marfey’s analysis with authentic standards. Rosβ is shown to have a unique ring pattern amongst previously characterized lanthipeptides. TOC graphic
Source: Journal of Natural Products
Language: English
Subfield: Microbiology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7128783201