abstract
- The rise and dissemination of glycopeptide antibiotic (GPA)-resistant pathogens in healthcare settings fuel efforts to discover GPAs that can overcome resistance. Members of the type V subclass of GPAs can evade common GPA resistance mechanisms and offer promise as new drug leads. We characterize five new type V GPAs-rimomycin-A/B/C and misaugamycin-A/B-discovered through a phylogeny-guided genome mining strategy coupled with heterologous production using our GPAHex synthetic biology platform. Rimomycin is a heptapeptide similar to kistamicin but includes an N-methyl-tyrosine at amino acid 6 (AA6) and substitutes 4-hydroxyphenylglycine for tyrosine and 3,5-dihydroxyphenylglycine at positions AA1 and AA3. Misaugamycin is characterized by an unprecedented N-C cross-link between AA2 and AA4 and unique N-terminal acylation by malonyl (misaugamycin-A) or 2-sulfoacetyl (misaugamycin-B) groups. We demonstrate that rimomycin-A/B/C and misaugamycin-A/B are potent antibiotics with activity against GPA-resistant clinical isolates and that the mode of action is consistent with the inhibition of cell division by the evasion of autolysin activity. These discoveries expand the chemical diversity of the type V GPAs, offer new chemical scaffolds for drug development, and demonstrate the application of the GPAHex platform in mining GPA chemical "dark matter".