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 PubMed
Bacteria sense their environment using receptors of the histidine sensor kinase family, but how kinase activity is regulated by ligand binding is not well understood. Autoinducer-2 (AI-2), a secreted signaling molecule originally identified in studies of the marine bacterium Vibrio harveyi, regulates quorum-sensing responses and allows communication between different bacterial species. AI-2 signal transduction in V. harveyi requires the integral membrane receptor LuxPQ, comprised of periplasmic binding protein (LuxP) and histidine sensor kinase (LuxQ) subunits. Combined X-ray crystallographic and functional studies show that AI-2 binding causes a major conformational change within LuxP, which in turn stabilizes a quaternary arrangement in which two LuxPQ monomers are asymmetrically associated. We propose that formation of this asymmetric quaternary structure is responsible for repressing the kinase activity of both LuxQ subunits and triggering the transition of V. harveyi into quorum-sensing mode.
Ligand-induced asymmetry in histidine sensor kinase complex regulates quorum sensing.,Neiditch MB, Federle MJ, Pompeani AJ, Kelly RC, Swem DL, Jeffrey PD, Bassler BL, Hughson FM Cell. 2006 Sep 22;126(6):1095-108. PMID:16990134[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Neiditch MB, Federle MJ, Pompeani AJ, Kelly RC, Swem DL, Jeffrey PD, Bassler BL, Hughson FM. Ligand-induced asymmetry in histidine sensor kinase complex regulates quorum sensing. Cell. 2006 Sep 22;126(6):1095-108. PMID:16990134 doi:http://dx.doi.org/10.1016/j.cell.2006.07.032
