Difference between revisions of "Part:BBa K1666004"

Revision as of 02:40, 19 September 2015

LsrK of LuxS/AI-2 signaling pathway in Salmonalla

Quorum sensing is a process of bacterial cell-to-cell communication involving the production and detection of extracellular signaling molecules called autoinducers. And autoinducer-2 (AI-2) has been proposed to serve as a 'universal signal' for interspecies communication. In the LuxS/AI-2 signaling system of Salmonella Typhimurium, AI-2 response involves ATP binding cassette transporter encoded by genes named Lsr (LuxS regulated). And LsrK is the kinase which catalyzes the phosphorylation of autoinducer 2 (AI-2) to phospho-AI-2. In our project, we set this protein-coding part under a nisA promoter and try to integrate them in the genome of Lactobacillus or Lactococcus for the final purpose of constructing an integrated AI-2 response pathway of Salmonella in the engineered bacteria.

Usage and Biology

AI-2 is generated by many species of Gram-negative and Gram-positive bacteria. In a group of bacteria exemplified by Salmonella, AI-2 response involves lsr genes that encode ATP binding cassette-type transporter. LsrK catalyzes the phosphorylation of autoinducer 2(AI-2) to phospho-AI-2, which subsequently inactivates the transcriptional regulator LsrR and leads to the transcription of the lsr operon.

Fig1. Schematic overview of the AI-2 response pathway in Salmonella TyphimuriumThe precursor of AI-2, 4,5-Dihydroxy-2,3-Pentanedione (DPD) , is a byproduct generated when LuxS converts S-Ribosylhomocysteine (SRH) to Homocysteine (HCY). DPD then undergoes spontaneously cyclization, forming AI-2, and exports to the culture supernatant. After that, extracellular AI-2 bounds to LsrB, following by passing the membrane channel and importing the cytoplasm. LsrK phosphorylates AI-2 afterwards. The lsr operon is repressed until phosphorylated AI-2 causes LsrR to relieve its repression on the promoter. And this allows further AI-2 import.

In our project, we set this protein-coding part under the regulation of a nisA promoter which can be activated by food-grade inducer, nisin. We linearized the related expression vectors and stably integrated them into the genome of the hosts. And together with other parts, we will construct a membrane channel for AI-2 generated by pathogens in the engineered bacteria.

Fig2. Part of the vector containing lsrK We use nisA promoter to initiate the transcription of lsrK gene

Sequence and Features

Assembly Compatibility:

10
COMPATIBLE WITH RFC[10]
12
COMPATIBLE WITH RFC[12]
21
COMPATIBLE WITH RFC[21]
23
COMPATIBLE WITH RFC[23]
25
INCOMPATIBLE WITH RFC[25]
Illegal AgeI site found at 61
1000
COMPATIBLE WITH RFC[1000]

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 __NOTOC__
 <partinfo>BBa_K1666004 short</partinfo>
-Quorum sensing is a process of bacterial cell-to-cell communication involving the production and detection of extracellular signaling molecules called autoinducers. And autoinducer-2 (AI-2) has been proposed to serve as a 'universal signal' for interspecies communication. In the LuxS/AI-2 signaling system of Salmonella Typhimurium, AI-2 response involves ATP binding cassette transporter encoded by genes named Lsr (LuxS regulated). And LsrK is the kinase which catalyzes the phosphorylation of autoinducer 2 (AI-2) to phospho-AI-2. In our project, we set this protein-coding part under a nisA promoter and try to integrate them in the genome of Lactobacillus or Lactococcus for the final purpose of constructing an integrated AI-2 response pathway of Salmonella in the engineered bacteria.
+Quorum sensing is a process of bacterial cell-to-cell communication involving the production and detection of extracellular signaling molecules called autoinducers. And autoinducer-2 (AI-2) has been proposed to serve as a 'universal signal' for interspecies communication. In the LuxS/AI-2 signaling system of ''Salmonella Typhimurium'', AI-2 response involves ATP binding cassette transporter encoded by genes named ''Lsr'' (LuxS regulated). And LsrK is the kinase which catalyzes the phosphorylation of autoinducer 2 (AI-2) to phospho-AI-2. In our project, we set this protein-coding part under a nisA promoter and try to integrate them in the genome of Lactobacillus or Lactococcus for the final purpose of constructing an integrated AI-2 response pathway of ''Salmonella'' in the engineered bacteria.
-<!-- Add more about the biology of this part here
 ===Usage and Biology===
+AI-2 is generated by many species of Gram-negative and Gram-positive bacteria. In a group of bacteria exemplified by ''Salmonella'', AI-2 response involves ''lsr'' genes that encode ATP binding cassette-type transporter. LsrK catalyzes the phosphorylation of autoinducer 2(AI-2) to phospho-AI-2, which subsequently inactivates the transcriptional regulator LsrR and leads to the transcription of the ''lsr'' operon.
+[[File:NEFU_China_2015_AI-2_response_in_Salmonalla.png|550px|thumb|center|'''Fig1. Schematic overview of the AI-2 response pathway in ''Salmonella Typhimurium'''''The precursor of AI-2, 4,5-Dihydroxy-2,3-Pentanedione (DPD) , is a byproduct generated when LuxS converts S-Ribosylhomocysteine (SRH) to Homocysteine (HCY). DPD then undergoes spontaneously cyclization, forming AI-2, and exports to the culture supernatant. After that, extracellular AI-2 bounds to LsrB, following by passing the membrane channel and importing the cytoplasm. LsrK phosphorylates AI-2 afterwards. The ''lsr'' operon is repressed until phosphorylated AI-2 causes LsrR to relieve its repression on the promoter. And this allows further AI-2 import.]]
+In our project, we set this protein-coding part under the regulation of a nisA promoter which can be activated by food-grade inducer, nisin. We linearized the related expression vectors and stably integrated them into the genome of the hosts. And together with other parts, we will construct a membrane channel for AI-2 generated by pathogens in the engineered bacteria.
+[[File:NEFU_China_2015_pnisA_and_LsrK.png|450px|thumb|center|'''Fig2. Part of the vector containing ''lsrK'' '''We use nisA promoter to initiate the transcription of ''lsrK'' gene]]
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