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

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.

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