Revision as of 12:19, 19 October 2021

pDawn-B0034-X174 E-rrnB T1

Description

This composite part is a generator consisting of the pDawn promoter and X174 E.

Sequence and Features

2021 SZPT-China

Biology

This composite part is a generator consisting of the pDawn (BBa_K1075044) promoter and X174 E (BBa_K1835500).

Usage

The target genes of pDawn blue light response system (BBa_K1075044) and X174 E (BBa_K1835500) were inserted into the pSEVA331 expression vector. Then, random primer guided mutagenesis method to modulate the strength of the RBS (BBa_B0034) located upstream of X174 E. Finally, the pDawn-RBSNNN-X174 E-rrnB T1 (BBa_K3740044) plasmid was constructed and introduced into E. coli. E. coli isolates that grow normally in the dark and cannot grow under blue light were screened out. Finally, the plasmid was extracted, and further introduced into G. hansenii ATCC 53582, in which the responsiveness of pDawn to blue light was also verified.

Figure 1. Gene circuit of pDawn-RBSNNN-X174 E-rrnB T1.

Characterization

1. Batch screening of pSEVA331-pDawn-RBSNNN-X174 E-rrnB T1- pSEVA331in response to blue light lysis in E. coli.

Method: We use the random primer method to modulate the strength of the RBS (BBa_B0034) located upstream of X174 E. After introducing into E. coli DH5α, a drop plate assay was performed to screen the bacterial isolate that can grow normally in the dark but cannot under the blue light irradiation.

As shown in Figure 11, the 4th isolate that grew normally in the dark but did not under blue light, indicating that we successfully expressed the cleavage protein X174 E in E. coli.

Figure 2：The growth status of pDawn-RBSNNN-X174 E-rrnB T1-pSEVA331-DH5α under blue light (a) and dark conditions (b).

2. pDawn-RBSNNN-X174 E-rrB T1-pSEVA331-7# in response to blue phptolysis in G. hansenii ATCC 53582

Method: We launched the liquid culture of pDawn-RBSNNN-X174 E-rrnB T1-pSEVA331-DH5α, extracted the plasmid and introduced into G. hansenii ATCC 53582. After 2 days of incubation, we selected 20 monoclonal to spot on two parallel new plates, which were incubated for another 2 days, with one under blue light and the other in the dark. The strains with obvious growth difference under different illumination conditions were preserved. The drop plate assay using this strain was repeated to verify the lysis effect of X174 E on G. hansenii ATCC 53582.

As shown in Figure 3 (a), G. hansenii ATCC 53582 strains under the dark condition exhibited better growth than those under blue light irradiation; (b) pDawn-RBSNNN-X174 E-rrnB T1-pSEVA331-G. hansenii ATCC 53582-7# showed a stable lysis effect under blue light illumination but not in the dark, indicating that we successfully expressed the cleavage protein X174E in G. hansenii ATCC 53582.

Figure 3. (a) The growth status of pDawn-RBSNNN-X174 E-rrnB T1-pSEVA331-G. hansenii ATCC 53582-4# under blue light (1) and dark condition (2). (b)The growth status of pDawn-RBSNNN-X174 E-rrnB T1-pSEVA331-G. hansenii ATCC 53582-7# under blue light (1) and dark condition (2).

References

[1] Witte A, Wanner G, Sulzner M, et al. Dynamics of PhiX174 protein E-mediated lysis of Escherichia coli[J]. Archives of Microbiology, 1992, 157(4):381-388.

Phi X 147 E Lysis Gene: BBa_K1835500