when transcription is carried out in vitro employing only purified escherichia coli rna polymerase , up to 20 times as many rna polymerase molecules pass through a particular terminator when transcription is initiated from the e. coli tac promoter unit , as compared to transcription initiated from the t7a1 or rrnb p2 promoters .
C0035681
rna polymerase
C0040649
transcription