Part:BBa_K4645015
The pH-antitoxin system
The pH-antitoxin system contains two gene pathways: pH-sensitive pathway, and toxin-antitoxin pathway. The pH-sensitive circuit can detect pH changes when engineered bacteria enter a cat's digestive tract and take effect, expressing CI protein to inhibit the expression of antitoxin protein MntA. At the same time, it expresses the two-component system RstAB. RstB can sense the decrease in pH to phosphorylate RstA, and RstA can increase the activity of the acid-induced promoter Pasr, thus quickly increasing the expression of CI protein. The toxin protein HepT and antitoxin protein MntA form a toxin-antitoxin pathway, where the expression of MntA protein is inhibited by CI protein.The circuit design is shown in the diagram below.
Basic Elements
Pasr is an acid sensitive promoter, in acid condition of PH5-6 , it could be activated .
CI protein is the regulatory protein of λ phage lysogenic cleavage pathway .
RstAB is a two-component system, RstB can sense the decrease in pH to phosphorylate RstA, and RstA can increase the activity of the acid-induced promoter Pasr.
HepT is a toxin, strongly inhibiting cell growth in S.oneidensis and Escherichia coli.