Characterization of the biosynthetic gene cluster of glycosylated antibiotic nocathiacin I (NOC-I) here adds new insights to thiopeptide biosynthesis, showing the NOC-specific tailoring and unusual sugar formation. NOC-I biosynthesis shares the paradigm for forming a common thiopeptide core and the generality for converting to an e series member, as that of the parent compound nosiheptide (NOS). This may permit the production of NOC-I in the genetically amenable, NOS-producing strain by building NOC-specific genes for pathway engineering.

Bacterial aromatic polyketides, exemplified by anthracyclines, angucyclines, tetracyclines, and pentangular polyphenols, are a large family of natural products with diverse structures and biological activities and are usually biosynthesized by type II polyketide synthases (PKSs). Since the starting point of biosynthesis and combinatorial biosynthesis in 1984–1985, there has been a continuous effort to investigate the biosynthetic logic of aromatic polyketides owing to the urgent need of developing promising therapeutic candidates from these compounds. Recently, significant advances in the structural and mechanistic identification of enzymes involved in aromatic polyketide biosynthesis have been made on the basis of novel genetic, biochemical, and chemical technologies. This review highlights the progress in bacterial type II PKSs in the past three years (2013–2016). Moreover, novel compounds discovered or created by genome mining and biosynthetic engineering are also included.