Figure 6.

Workflow of the double switch system. (A) pSJ27-Φ11dut vector was electroporated into the Stl switch system. The relatively high expression level of Φ11 phage dUTPase enzyme is provided by a heat shock protein promoter (Phsp65). Φ11 phage dUTPase is a known partner of Stl, able to promote Stl to release the regulated DNA [24,28]; (B) Validation of the detection of protein:protein interaction using the LacZ^Str reporter system. Stl in complex with Φ11 phage dUTPase releases DNA, therefore, blue colonies are formed. Note that the number of colonies represents the transformation efficiency.