Enzymatic and Mutational Analysis of the PruA Pteridine Reductase Required for Pterin-Dependent Control of Biofilm Formation in Agrobacterium tumefaciens

Abstract

Biofilms are complex multicellular communities that are formed by diverse bacteria. In the plant pathogen Agrobacterium tumefaciens , the transition from a free-living motile state to a nonmotile biofilm state is governed by a novel signaling pathway involving small molecules called pterins. The involvement of pterins in biofilm formation is unexpected and prompts many questions about the molecular details of this pathway. This work biochemically characterized the PruA pteridine reductase involved in the signaling pathway to reveal its enzymatic properties and substrate preference, thus providing important insight into pterin biosynthesis and its role in A. tumefaciens biofilm control. Additionally, the enzymatic characteristics of related pteridine reductases from mammalian pathogens were examined to uncover potential roles of these enzymes in other bacteria.