Eukaryotic promoters drive gene expression in Escherichia coli

Eight eukaryotic promoters have been tested for their activity in vivo in Escherichia coli. The rat beta-actin, rat amylase, rat chymotrypsin B, mouse metallothionein I, rat insulin I, human insulin, Rous sarcoma virus long terminal repeat (RSV LTR) and hepatitis B viral precore promoter activities were measured by using the bacterial chloramphenicol acetyltransferase coding sequences as the reporter function and by primer extension RNA analysis. All eight promoter-chloramphenicol acetyltransferase constructs produce chloramphenicol acetyltransferase activity with the following relative strengths: RSV LTR greater than rat beta-actin greater than rat insulin I greater than rat amylase greater than hepatitis B virus precore greater than human insulin greater than rat chymotrypsin B greater than mouse metallothionein I. A primer extension analysis indicates that transcription from the RSV LTR, rat insulin I, and rat beta-actin promoters initiates at the sites expected for eukaryotic rather than prokaryotic promoters. Thus the site of initiation is determined by the DNA sequence rather than by the RNA polymerase.