title: LsrF, a coenzyme A-dependent thiolase, catalyzes the terminal step in processing the quorum sensing signal autoinducer-2.
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.
authors.affiliation: Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal; Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Av. de Brasilia, 1400-038 Lisbon, Portugal;
authors.forename: João C
authors.initials: JC
authors.lastname: Marques
authors.affiliation: Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081; and.
authors.forename: Il Kyu
authors.initials: IK
authors.lastname: Oh
authors.affiliation: Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081; and.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Ly
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Lamosa
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal.
authors.forename: M Rita
authors.initials: MR
authors.lastname: Ventura
authors.affiliation: Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081; and smiller1@swarthmore.edu kxavier@igc.gulbenkian.pt.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Miller
authors.affiliation: Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal; Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal smiller1@swarthmore.edu kxavier@igc.gulbenkian.pt.
authors.forename: Karina B
authors.identifier: http://orcid.org/0000-0001-5210-1434
authors.initials: KB
authors.lastname: Xavier
mesh_terms: D000123:Acetyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019943:Amino Acid Substitution; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003065:Coenzyme A / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006714:Homoserine / Q000031:analogs & derivatives* / Q000378:metabolism; D007700:Kinetics; D007783:Lactones / Q000378:metabolism*; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D053038:Quorum Sensing
chemical_list: D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D007783:Lactones; C555903:LsrB protein, E coli; C091088:N-octanoylhomoserine lactone; D006714:Homoserine; D000123:Acetyltransferases; D003065:Coenzyme A
keywords: bacterial communication; cell–cell signaling; metabolic flux; quorum quenching