Difference between revisions of "Part:BBa K4442001"
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The pchA promoter, pchA, and LEE1 promoter sequences were all obtained from the original study authors, Yanfen Bai and Thomas J. Mansell. | The pchA promoter, pchA, and LEE1 promoter sequences were all obtained from the original study authors, Yanfen Bai and Thomas J. Mansell. | ||
| + | ==2023 NMU_China== | ||
Revision as of 09:49, 6 October 2023
The butyrate sensing system PpchA-PLEE1 originates from the enterohemorrhagic Escherichia coli strain O157:H7 which was discovered by Nakanishi et al. (2009). The system below includes the sequences of the pchA promoter and pchA regulator, located upstream, as well as the LEE1 promoter and RBS downstream. A complex of the leucine-responsive regulatory protein and butyrate activates the system. To add an fluorescent output or any other sort of output protein, simply add the base pairs downstream of the RBS.
Nakanishi et al.1 found that the leucine-responsive regulatory protein (Lrp) forms a complex with butyrate which after binding to the promoter of pchA, activates the transcription of the pchA regulator. The pchA regulator then binds to the promoter of LEE1, to transcribe the ler gene. In Bai & Mansell’s2 paper, the ler gene was replaced with GFP to report the sensing of butyrate. Similarly, in our project, the pchA regulator would bind to the promoter of LEE1 but instead express YFP.
More information can be obtained here: Nakanishi N, Tashiro K, Kuhara S, Hayashi T, Sugimoto N, Tobe T. Regulation of virulence by butyrate sensing in enterohaemorrhagic escherichia coli. Microbiology. 2009;155(2):521–30. Bai Y, Mansell TJ. Production and sensing of butyrate in a probiotic E. coli strain. International Journal of Molecular Sciences. 2020;21(10):3615.
A decrease in butyrate concentration in fecal samples was found to correlate with depression. As part of our goal to create a microbial sensor to aide in the diagnosis of depression, this system will allow us to detect the levels of butyrate through fluorescence intensity.
The pchA promoter, pchA, and LEE1 promoter sequences were all obtained from the original study authors, Yanfen Bai and Thomas J. Mansell.