title: Ligand binding kinetics of the quorum sensing regulator PqsR.
abstract: The Pseudomonas aeruginosa quinolone signal (PQS) is a quorum sensing molecule that plays an important role in regulating the virulence of this organism. We have purified the ligand binding domain of the receptor PqsRLBD for PQS and have used Förster resonance energy transfer fluorimetry and kinetic modeling to characterize the ligand binding in vitro. The dissociation constant for binding of PQS to a ligand binding site in (PqsRLBD)2 dimers was determined to be 1.2 ± 0.3 μM. We found no cooperativity in the consecutive binding of two ligand molecules to the dimer.
authors.affiliation: Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB21QW, United Kingdom. mw240@cam.ac.uk
authors.forename: Martin
authors.initials: M
authors.lastname: Welch
authors.forename: James T
authors.initials: JT
authors.lastname: Hodgkinson
authors.forename: Jeremy
authors.initials: J
authors.lastname: Gross
authors.forename: David R
authors.initials: DR
authors.lastname: Spring
authors.forename: Thomas
authors.initials: T
authors.lastname: Sams
mesh_terms: D031541:Fluorescence Resonance Energy Transfer; D008024:Ligands; D008958:Models, Molecular; D011485:Protein Binding; D011550:Pseudomonas aeruginosa / Q000737:chemistry* / Q000378:metabolism* / Q000472:pathogenicity; D015363:Quinolones / Q000737:chemistry* / Q000378:metabolism*; D053038:Quorum Sensing / Q000502:physiology*; D014774:Virulence
chemical_list: C407944:2-heptyl-3-hydroxy-4-quinolone; D008024:Ligands; D015363:Quinolones