1zhh
From Proteopedia
Crystal Structure of the Apo Form of Vibrio Harveyi LUXP Complexed with the Periplasmic Domain of LUXQ
Structural highlights
Function[LUXP_VIBHA] Binds to the signaling molecule autoinducer 2 (AI-2), a furanosyl borate diester, (3a-methyl-5,6-dihydrofuro-[2,3d][1,3,2]dioxaborole-2,2,6,6a-tetraol). This complex then interacts with the LuxQ sensor protein. [LUXQ_VIBHA] At low cell density, in absence of AI-2 (autoinducer 2), LuxQ has a kinase activity and autophosphorylates on a histidine residue. The phosphoryl group is then transferred to an aspartate residue in the response regulator domain. The phosphoryl group is transferred to LuxU, and ultimately to LuxO. At high cell density, in the presence of AI-2, the kinase activity is inactivated, and the response regulator domain has a phosphatase activity. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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. Regulation of LuxPQ receptor activity by the quorum-sensing signal autoinducer-2.,Neiditch MB, Federle MJ, Miller ST, Bassler BL, Hughson FM Mol Cell. 2005 May 27;18(5):507-18. PMID:15916958[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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