LsrF, a coenzyme A-dependent thiolase, catalyzes the terminal step in processing the quorum sensing signal autoinducer-2.
The quorum sensing signal autoinducer-2 (AI-2) regulates important bacterial behaviors, including biofilm formation and the production of virulence factors. Some bacteria, such as Escherichia coli, can quench the AI-2 signal produced by a variety of species present in the environment, and thus can influence AI-2-dependent bacterial behaviors. This process involves uptake of AI-2 via the Lsr transporter, followed by phosphorylation and consequent intracellular sequestration. Here we determine the metabolic fate of intracellular AI-2 by characterizing LsrF, the terminal protein in the Lsr AI-2 processing pathway. We identify the substrates of LsrF as 3-hydroxy-2,4-pentadione-5-phosphate (P-HPD, an isomer of AI-2-phosphate) and coenzyme A, determine the crystal structure of an LsrF catalytic mutant bound to P-HPD, and identify the reaction products. We show that LsrF catalyzes the transfer of an acetyl group from P-HPD to coenzyme A yielding dihydroxyacetone phosphate and acetyl-CoA, two key central metabolites. We further propose that LsrF, despite strong structural homology to aldolases, acts as a thiolase, an activity previously undescribed for this family of enzymes. With this work, we have fully characterized the biological pathway for AI-2 processing in E. coli, a pathway that can be used to quench AI-2 and control quorum-sensing-regulated bacterial behaviors.
Published In/Presented At
Marques, J. C., Oh, I. K., Ly, D. C., Lamosa, P., Ventura, M. R., Miller, S. T., & Xavier, K. B. (2014). LsrF, a coenzyme A-dependent thiolase, catalyzes the terminal step in processing the quorum sensing signal autoinducer-2. Proceedings of the National Academy of Sciences of the United States of America, 111(39), 14235–14240. https://doi.org/10.1073/pnas.1408691111
Medicine and Health Sciences | Pediatrics
Department of Pediatrics