LsrF, a coenzyme A-dependent thiolase, catalyzes the terminal step in processing the quorum sensing signal autoinducer-2.
Marques, J.C., Oh, I.K., Ly, D.C., Lamosa, P., Ventura, M.R., Miller, S.T., Xavier, K.B.(2014) Proc Natl Acad Sci U S A 111: 14235-14240
- PubMed: 25225400 
- DOI: https://doi.org/10.1073/pnas.1408691111
- Primary Citation of Related Structures:  
4P2V - PubMed Abstract: 
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.
Organizational Affiliation: 
Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal; Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Av. de Brasilia, 1400-038 Lisbon, Portugal;