Fig 4.

Relative AP activity of E. coli DH5α strains harboring relevant expression constructs. All values are relative to the CSP result, which was arbitrarily set to 1. AP, endogenous AP signal sequence (pASP1phoA construct); CSP, original sequence (pCSP1phoA construct), while S2, S38, S48, S60, and S61 indicate the variant CSP sequences in pCSP1S2phoA, pCSP1S38phoA, pCSP1S48phoA, pCSP1S60phoA, and pCSP1S61phoA, respectively. Cultures were induced by 0.1 mM m-toluic acid. All results are the averages of two biological replicas with at least three samples, and the standard errors are indicated.