Bacterial promoter activity following insertion of the <i>trpA</i> bacterial transcription terminator.

<p>(A) Western immunoblots showing expression of C-fragment from <i>S. typhimurium</i> BRD509 containing pcDNA3/Cfrag (CMV), pcDNA3/Cfrag-T (T) or pcDNA3/Cfrag-P1/2-T (P1/2T). Purified C-fragment (pos) and BRD509 alone (neg) were included as controls. (B) To quantify promoter activity, the unmodified pCMV (CMV), pCMV-T (T) and pCMV-P1/2-T (P1/2T) were cloned into the β-galactosidase vector and promoter activity expressed as units of β-galactosidase activity. Activity of the empty vector (neg) is included as a negative control.