Enzyme function and mechanism in peptidyl nucleoside antibiotic biosynthesis

The rapid increase in multiple drug resistant bacteria has detrimentally impacted the clinical utility of several antibiotics, a problem that is compounded by the steady decline in the FDA approval of new antibacterial drugs. We have developed a screen aimed at identifying novel antibiotics that are inhibitors of a previously unexploited cellular target, bacterial translocase I, which is an essential enzyme involved in peptidoglycan cell wall biosynthesis. This screen has led to the discovery of several uridine-based peptidyl nucleoside antibiotics produced by various actinomycetes. We have now identified the biosynthetic genes for several of these translocase I inhibitors, and our biochemical studies have unearthed several interesting enzymatic transformations including an ATP-independent mechanism of amide bond formation, a novel glycosylation pathway, and an unusual transaldolation strategy to generate so-called high carbon sugar nucleosides. These results, along with how this biochemical knowledge has been utilized to generate novel analogues, will be presented.