Difference between revisions of "Part:BBa K131015"

Revision as of 01:41, 30 October 2008

LuxPQ from Vibrio harveyi

LuxP is a ABC-type sugar transport system periplasmic protein (Protein ID = YP_001447483.1). LuxQ is a histidine kinase (Protein ID = YP_001447484.1).

Sequence and Features

Assembly Compatibility:

10
COMPATIBLE WITH RFC[10]
12
COMPATIBLE WITH RFC[12]
21
INCOMPATIBLE WITH RFC[21]
Illegal BglII site found at 2209
Illegal BglII site found at 2427
23
COMPATIBLE WITH RFC[23]
25
COMPATIBLE WITH RFC[25]
1000
INCOMPATIBLE WITH RFC[1000]
Illegal BsaI.rc site found at 3509
Illegal SapI.rc site found at 2177

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 __NOTOC__
 <partinfo>BBa_K131015 short</partinfo>
 LuxPQ from Vibrio harveyi
 LuxP is a ABC-type sugar transport system periplasmic protein (Protein ID = YP_001447483.1).
 LuxQ is a histidine kinase (Protein ID = YP_001447484.1).
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 <!-- Add more about the biology of this part here
 ===Usage and Biology===
+Quorum-sensing bacteria produce and release chemical signal molecules termed autoinducers (AIs) whose external concentration increases as a function of increasing cell-population density. Bacteria detect the accumulation of a minimal threshold stimulatory concentration of these autoinducers and alter gene expression, and therefore their behavior. Using these signal-response systems, bacteria synchronize particular behaviors on a population-wide scale and thus function as multicellular organisms.
+The bioluminescent marine bacterium Vibrio harveyi uses three different AIs—AHL, CAI-1, and AI-2—to control the expression of genes responsible for bioluminescence and numerous other traits. We have designed our System 2 based on V. harveyi AI-2 signaling.
+V. harveyi AI-2 signal is a furanosyl borate diester, production of which requires the LuxS enzyme. AI-2 is bound in the periplasm by the protein LuxP. The LuxP-AI-2 complex interacts with another membrane-bound sensor histidine kinase, LuxQ. At low cell density, in the absence of significant amounts of autoinducers, LuxQ acts as kinase, autophosphorylate, and subsequently transfer the phosphate to the cytoplasmic protein LuxU. LuxU passes the phosphate to the DNA-binding response regulator protein LuxO. Phospho-LuxO, in conjunction with a transcription factor termed σ54, activates transcription of the genes encoding five regulatory small RNAs (sRNAs) termed Qrr1–5 (for Quorum Regulatory RNA). The Qrr sRNAs interact with an RNA chaperone termed Hfq, involved in mRNA splicing. The sRNAs, together with Hfq, bind to and destabilize the mRNA encoding the transcriptional activator termed LuxR. LuxR is required to activate transcription of the luciferase operon luxCDABE.
+Thus, at low cell density, because the luxR mRNA is degraded, the bacteria do not express bioluminescence. At high cell density, when the autoinducers accumulate to the level required for detection, the LuxQ switches from being kinases to being phosphatases and drain phosphate from LuxO via LuxU. Unphosphorylated LuxO cannot induce expression of the sRNAs. This allows translation of luxR mRNA, production of LuxR, and expression of bioluminescence.
+Reference:
+Waters C.M. and Bassler B.L. Quorum sensing: cell-to-cell communication in bacteria.
+Annu Rev Cell Dev Biol. 2005;21:319-46.
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