Difference between revisions of "Part:BBa K2762014"

Revision as of 06:51, 29 September 2018

P_asr-B0034-sfGFP

Characterization

The asr promoter was first described by Suziedeliene et al. in 1999. They showed that asr is induced under low pH which is about pH 4.8, and it is controlled by the phoBR system. From the article they have published, the promoter is named as acid shock RNA (asr) promoter due to the RNA that has been transcribed after putting the E. coli into a low pH condition.

In 2007 Ogasawara et al2. found out that there is another regulatory system that controlling asr transcription by using SELEX to find the binding sequences of PhoQP-RstBA. Hence the asr promoter is directly controlled by two different systems, the PhoBR system activated through low inorganic phosphate and the RstAB system sensing the pH while it is controlled by PhoQP-system activated by low Mg²⁺ concentrations.

Our team have cloned this gene and also a sfGFP gene downstream of this promoter which could express green fluorescent once the promoter has been activated. In conclusion, we could monitor the pH in the surrounding medium in our device at any time by observing the color change of the medium.

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 314
1000
COMPATIBLE WITH RFC[1000]

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 ===Characterization===
-The strain that we used is carrying asr promoter, a pH-responsive promoter which is native to <i>E. coli</i> and it could induce transcription in acidic conditions. Besides, we clone a sfGFP gene downstream of this promoter which could express green fluorescent once the promoter has been activated.
+The asr promoter was first described by Suziedeliene et al. in 1999. They showed that asr is induced under low pH which is about pH 4.8, and it is controlled by the phoBR system. From the article they have published, the promoter is named as acid shock RNA (asr) promoter due to the RNA that has been transcribed after putting the <i>E. coli</i> into a low pH condition.
-In conclusion, when the color of the medium turns from turbid yellow to green,  it indicates the pH of the medium is too low so the medium should be changed as it is not suitable for our <i>E. coli</i> to grow.
+In 2007 Ogasawara et al2. found out that there is another regulatory system that controlling asr transcription by using SELEX to find the binding sequences of PhoQP-RstBA. Hence the asr promoter is directly controlled by two different systems, the PhoBR system activated through low inorganic phosphate and the RstAB system sensing the pH while it is controlled by PhoQP-system activated by low Mg<sup>2+</sup> concentrations.
-The asr promoter was first described by Suziedeliene et al. in 1999. They showed that asr is induced under low pH which is about pH 4.8, and it is controlled by the phoBR system. From the article they have published, the promoter is named as acid shock RNA (asr) promoter due to the RNA that has been transcribed after putting the E. coli into a low pH condition.
+Our team have cloned this gene and also a sfGFP gene downstream of this promoter which could express green fluorescent once the promoter has been activated. In conclusion, we could monitor the pH in the surrounding medium in our device at any time by observing the color change of the medium.
-In 2007 Ogasawara et al2. found out that there is another regulatory system that controlling asr transcription by using SELEX to find the binding sequences of PhoQP-RstBA. Hence the asr promoter is directly controlled by two different systems, the PhoBR system activated through low inorganic phosphate and the RstAB system sensing the pH while it is controlled by PhoQP-system activated by low Mg<sup>2+</sup> concentrations.
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