ABSTRACT
Actinobacteria have been a rich source of novel, structurally complex natural products for many decades. Although the largest genus is Streptomyces, from which the majority of antibiotics in current and past clinical use were originally isolated, other less common genera also have the potential to produce a wealth of novel secondary metabolites. One example is the Kutzneria genus, which currently contains only five reported species. One of these species is Kutzneria albida DSM 43870T, which has 46 predicted biosynthetic gene clusters and is known to produce the macrolide antibiotic aculeximycin. Here, we report the isolation and structural characterization of two novel 30-membered glycosylated macrolides, epemicins A and B, that are structurally related to aculeximycin, from a rare Kutzneria sp. The absolute configuration for all chiral centers in the two compounds is proposed based on extensive 1D and 2D NMR studies and bioinformatics analysis of the gene cluster. Through heterologous expression and genetic inactivation, we have confirmed the link between the biosynthetic gene cluster and the new molecules. These findings show the potential of rare Actinobacteria to produce new, structurally diverse metabolites. Furthermore, the gene inactivation represents the first published report to genetically manipulate a representative of the Kutzneria genus.
Subject(s)
Actinobacteria/chemistry , Anti-Bacterial Agents/pharmacology , Macrolides/pharmacology , Actinobacteria/genetics , Actinobacteria/metabolism , Anti-Bacterial Agents/biosynthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Drug Discovery , Macrolides/chemistry , Macrolides/isolation & purification , Macrolides/metabolism , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Multigene Family , Polyketide Synthases/chemistry , Polyketide Synthases/genetics , Polyketide Synthases/metabolism , Protein Domains , StereoisomerismABSTRACT
To accelerate the shift to bio-based production and overcome complicated functional implementation of natural and artificial biosynthetic pathways to industry relevant organisms, development of new, versatile, bio-based production platforms is required. Here we present a novel yeast-based platform for biosynthesis of bacterial aromatic polyketides. The platform is based on a synthetic polyketide synthase system enabling a first demonstration of bacterial aromatic polyketide biosynthesis in a eukaryotic host.
