Part:BBa_K3376003
S. mutans thiol peroxidase promoter (tpxp)
Thiol peroxidase of S. mutans plays a role in cell protection against oxidative stress by catalyzing the reduction of H2O2 to water. The gene expression is correlated to the concentration of H2O2. Thiol peroxidase promoter (tpxp) activity is induced by the presence of H2O2. The promoter was cloned out from the gDNA of S. mutans and tested in transformed E. coli.
Expression
The fluorescence expression levels were measured for lactate dehydrogenase promoter (ldhp) [ldhp-GFP-Tr/pSB1C3 (BBa_K3376002)] and thiol peroxidase promoter (tpxp) [tpxp-GFP-Tr/pSB1C3 (BBa_K3376004)] activity of S. mutans. GFP was detected at Ex/Em = 483/513. As shown in the figure, the expression level of tpxp-driven GFP was limited compared to a strong and constitutive promoter (ldhp).
Regulation
The tpxp-GFP-Tr/pSB1C3 [BBa_K3376002] and ldhp-AQP-Tr-tpxp-GFP-Tr/pSB1C3 [BBa_K3376007] were transformed into E. coli Nissle strain. Because of the limited H2O2 diffusion across the cell membrane, the tpxp activity was not changed in the presence of H2O2. In aid of expression of aquaporin (AQP) to facilitate H2O2 permeation, the tpxp-driven GFP levels were enhanced by the increasing amounts of H2O2 in a dose-dependent manner.
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]
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