Difference between revisions of "Part:BBa K3137014"

Latest revision as of 20:26, 21 October 2019

responce circuit

Usage and Biology

The responce gene circuit is composed of an inducible promoter PputA(BBa_K3137002) and anti-phage protein genes of the incubation period (about 5 min), and an inducible promoter PglcF (BBa_K3137003) and a toxic protein gene protegrin-1(BBa_K62800) of the burst period (about 20 min).

When E. coli is infected by a phage, responce gene circuit is induced to express. When a phage infects E. coli into the incubation period (about 5 min), the inducible promoter PputA will induce the bacteria to express the resistant proteins (BBa_K3137006)(BBa_K3137005).

If the resistant proteins successfully resist phage infection, the inducible promoter PglcF will not induce the expression of downstream gene. If the resistant proteins fail to kill phages, it means that phages will continue to infect bacteria, when it comes to the burst period (around 20 min) of phage infection, the inducible promoter PglcF will activate the expression of downstream toxic protein gene so that the bacteria will lyse cells before the assembly of phages.

We performed the phage infection assay on the LB agar plate, and got very good resistance.

Figure 1. Resistance for T4 phage of E. coli BL21-pET28a-Pputa-abpAB-gntR-PglcF-P-1.

In addition, we inoculated E. coli BL21 and recombinant E. coli BL21-pET28a-PputA-abpAB-gntR-PglcF-P-1 in LB liquid medium to raise the logarithmic growth phase, i.e. OD 0.6-0.8 . Then the fresh phage solution was inoculated at the same time and culture was continued for 1-2 h. As a result, it was found that the recombinant grew well.

Figure 2. Resistance test for T4 phage of E. coli BL21-pET28a-Pputa-abpAB-gntR-PglcF-P-1 in flasks.

Sequence and Features