Difference between revisions of "Part:BBa K3205005"

Revision as of 17:01, 15 October 2019

luxPR_4G12T

The expression of this promoter can be up-regulated by the activation of LuxR activator protein which can form a complex with an autoinducer, 3-oxo-hexanoyl-HSL. This complex can bind to the upstream regulatory element of the promoter and increase the rate of the transcription. According to the theory above we can design a plasmid which constitutively expresses LuxR on the upstream of luxPR and a gene of interest expressed by luxPR. Protein of interest can be simply expressed by adding HSL into the medium. The promoter was improved from BBa_R0062. We mutated the T on its fourth site to G, and the C on its twelfth site to T. Comparing to the original part, the new part needs a higher HSL concentration to be activated. Implementing this mutation, we gained an improved luxPR with low leakage, high threshold without losing its highest intensity. The significant meaning of this improvement is that it can apparently delay the positive feedback of the quorum-sensing circuit, which will provide an ideal promoter for our project.

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 1
1000
COMPATIBLE WITH RFC[1000]

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 <partinfo>BBa_K3205005 short</partinfo>
-This promoter expresses downstream gene weakly. The expression of this promoter could be up-regulated by the activation of LuxR activator protein which complexed with autoinducer, 3-oxo-hexanoyl-HSL. Two molecules of LuxR protein and two molecules of the signal compound homoserine lactone (HSL) can form a complex. This complex could bind to a palindromic site of the promoter and increase the rate of the transcription. We can design a plasmid which contain a LuxR sequence on the upstream and a gene of interest on the downstream of the promoter. When we want to express the protein of interest, we can add homoserine lactone (HSL) in the medium.
+The expression of this promoter can be up-regulated by the activation of LuxR activator protein which can form a complex with an autoinducer, 3-oxo-hexanoyl-HSL. This complex can bind to the upstream regulatory element of the promoter and increase the rate of the transcription. According to the theory above we can design a plasmid which constitutively expresses LuxR on the upstream of luxPR and a gene of interest expressed by luxPR. Protein of interest can be simply expressed by adding HSL into the medium.
-The promoter was improved from BBa_R0062. We mutate the T of the fourth base to G, and the C of the twelfth to T. Comparing to the original part, the new part needs higher homoserine lactone (HSL) concentration to activate this promoter&#65292;thus decreasing its leakage.
+The promoter was improved from BBa_R0062. We mutated the T on its fourth site to G, and the C on its twelfth site to T. Comparing to the original part, the new part needs a higher HSL concentration to be activated. Implementing this mutation, we gained an improved luxPR with low leakage, high threshold without losing its highest intensity.
+The significant meaning of this improvement is that it can apparently delay the positive feedback of the quorum-sensing circuit, which will provide an ideal promoter for our project.