Figure 4.

Elongation factors NusA and NusG preferentially target his and ops pause complexes, respectively. [α-³²P]CTP-labeled A29 complexes (40 nM) were preformed on his or ops pause templates. Transcription was allowed to resume in the absence of additional factors (Left) or in the presence of 50 nM NusA (Center) or NusG (Right). The pause half-life and efficiency (see Materials and Methods) are indicated below each panel.