Part:BBa_M33001
Nar operon promoter (narGp) => PoPs
The narG promoter is located at the beginning the nar operon and is naturally activated during nitrate respiration of E. Coli by the Fnr protein to signal reduction of nitrate to nitrite. In the presence of nitrate, the L28H-fnr protein binds to a region upstream of narGp to act as an activator, releasing an outgoing PoPs signal from narGp. The exact mechanism of nitrate induction in the presence of L28H-fnr is not totally understood.
The nar operon consists of three subunits of nitrate reductase in E. Coli: narG, narH, and narI. The promoter for the operon as a whole is called the narG promoter (narGp) because the first subunit of this operon is narG. Classically, the promoter is known to be positively induced by the fnr (Fumarate nitrate reductase) gene product in the absence of oxygen. Yet under aerobic conditions, it is induced by the narL gene product in the presence of nitrate (Li, Rabi, DeMoss 1985). Recently, the promoter was also found to be positively induced by a fnr* (a mutant fnr protein with a Histidine substitution on Leucine 28) in the presence of nitrate (DeAngelis, Ji, Firestone, Lindlow 2005). It can thus be used to detect nitrate in the presence of narL or fnr*, or be used to detect oxygen availability for E. Coli in the presence of fnr.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
| None |