Biosynthetic Pathway for Mannopeptimycins, Lipoglycopeptide Antibiotics Active against Drug-Resistant Gram-Positive Pathogens

Abstract

The mannopeptimycins are a novel class of lipoglycopeptide antibiotics active against multidrug-resistant pathogens with potential as clinically useful antibacterials. This report is the first to describe the biosynthesis of this novel class of mannosylated lipoglycopeptides. Included here are the cloning, sequencing, annotation, and manipulation of the mannopeptimycin biosynthetic gene cluster from Streptomyces hygroscopicus NRRL 30439. Encoded by genes within the mannopeptimycin biosynthetic gene cluster are enzymes responsible for the generation of the hexapeptide core (nonribosomal peptide synthetases [NRPS]) and tailoring reactions (mannosylation, isovalerylation, hydroxylation, and methylation). The NRPS system is noncanonical in that it has six modules utilizing only five amino acid-specific adenylation domains and it lacks a prototypical NRPS macrocyclizing thioesterase domain. Analysis of the mannopeptimycin gene cluster and its engineering has elucidated the mannopeptimycin biosynthetic pathway and provides the framework to make new and improved mannopeptimycins biosynthetically.