Part:BBa_K3411020
NarP Nitrate/Nitrite Sensor
Lambert_GA iGEM 2020's novel NarP system, BBa_K3411020, is also modeled after E.coli’s natural nitrite sensor in the NAR Operon. Because the NarL system (BBa_K1682018) detects nitrate, Lambert iGEM needed a method to detect levels of nitrite: NarP, which detects both nitrate and nitrite. By calculating the corrected difference, the system would have concentrations for both nutrients. Lambert iGEM’s novel NarP composite part BBa_K3411020 and the NarP gene BBa_K3411010 are also modeled after E.coli’s natural nitrite sensor. Similarly to NarL, the promoter BBa_J23106, a constitutive Anderson Promoter, produces TetR, which represses the PtetO promoter, producing NarP. By regulating the amount of aTc, the molecule that inhibits TetR, the lab can control NarP’s expression, the product of the PtetO promoter. NarQ, the native membrane-bound protein, senses the amount of nitrate and/or nitrite in the cell: in the presence of nitrite and/or nitrate, NarQ will phosphorylate NarP, activating it, but if there is no nitrite and/or nitrate present, NarQ will not phosphorylate NarP [1]. If NarP is phosphorylated, it will activate the nirB promoter, producing GFP [2]. Lambert iGEM plans to correlate GFP levels to nitrite through mathematical modeling.
Lambert_GA iGEM 2020's plans on cloning and characterizing our NarP composite part in the coming year as a part of our two-year project, AgroSense.
References
[1] Darwin A.J., & Stewart V. (1996) The NAR Modulon Systems: Nitrate and Nitrite Regulation of Anaerobic Gene Expression. In: Regulation of Gene Expression in Escherichia coli. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-8601-8_17 [2] Wang H., & Gunsalus R. (2000). The nrfA and nirB Nitrite Reductase Operons in Escherichia coli Are Expressed Differently in Response to Nitrate than to Nitrite. Journal of Bacteriology, 182(20): 5813–5822. doi: 10.1128/jb.182.20.5813-5822.2000
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12INCOMPATIBLE WITH RFC[12]Illegal NheI site found at 2000
Illegal NheI site found at 2023 - 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25INCOMPATIBLE WITH RFC[25]Illegal NgoMIV site found at 2727
Illegal AgeI site found at 1371 - 1000COMPATIBLE WITH RFC[1000]
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