Enzymatic Strategies for the Catabolism of Organophosphonates

Abstract

Organophosphonates (Pns) are defined by a hydrolytically and thermally stable carbon-phosphorus bond. Although often thought of as synthetic creations, Pns also occur naturally as products of microbial biosynthesis. Many of these compounds, such as fosfomycin, dehydrophos, and bialaphos, are notable for their structural complexity and bioactivities. A subset of simpler Pns, such as methylphosphonic acid and 2-aminoethylphosphonic acid, are incorporated into biomolecules such as lipids, oligosaccharides, and glycoproteins. Such Pns are utilized by bacteria as a source of inorganic phosphate (Pi) when this nutrient is scarce in the environment. A number of different enzymatic pathways have evolved to convert Pns into Pi, which feature enzymes that cleave C-P bonds through heterolytic, oxidative, and radical mechanisms. The mechanisms and structures of these C-P bond cleaving enzymes are the focus of this article.