Regulation of LuxPQ receptor activity by the quorum-sensing signal autoinducer-2.

TitleRegulation of LuxPQ receptor activity by the quorum-sensing signal autoinducer-2.
Publication TypeJournal Article
Year of Publication2005
AuthorsNeiditch, MB, Federle, MJ, Miller, ST, Bassler, BL, Hughson, FM
JournalMol Cell
Date Published2005 May 27
KeywordsAmino Acid Sequence, Bacterial Proteins, Crystallography, X-Ray, Homoserine, Lactones, Luminescent Proteins, Models, Molecular, Molecular Sequence Data, Multiprotein Complexes, Phosphotransferases, Protein Binding, Protein Conformation, Protein Folding, Signal Transduction, Transcription Factors, Vibrio

<p>The extracellular signaling molecule autoinducer-2 (AI-2) mediates quorum-sensing communication in diverse bacterial species. In marine vibrios, binding of AI-2 to the periplasmic receptor LuxP modulates the activity of the inner membrane sensor kinase LuxQ, transducing the AI-2 information into the cytoplasm. Here, we show that Vibrio harveyi LuxP associates with LuxQ in both the presence and absence of AI-2. The 1.9 A X-ray crystal structure of apoLuxP, complexed with the periplasmic domain of LuxQ, reveals that the latter contains two tandem Per/ARNT/Simple-minded (PAS) folds. Thus, although many prokaryotic PAS folds themselves bind ligands, the LuxQ periplasmic PAS folds instead bind LuxP, monitoring its AI-2 occupancy. Mutations that disrupt the apoLuxP:LuxQ interface sensitize V. harveyi to AI-2, implying that AI-2 binding causes the replacement of one set of LuxP:LuxQ contacts with another. These conformational changes switch LuxQ between two opposing enzymatic activities, each of which conveys information to the cytoplasm about the cell density of the surrounding environment.</p>

Alternate JournalMol Cell
PubMed ID15916958
Grant ListAI-054442 / AI / NIAID NIH HHS / United States
GM-065859 / GM / NIGMS NIH HHS / United States