Figure 1.

Binding of NusA to RNA in the presence of the RNA polymerase α subunit. (A) Addition of increasing amounts of α to a constant amount of NusA results in an increase in complex formation. Reactions containing ³²P-labeled nut-site RNA and various combinations of 14 μM NusA and 1.25, 2.5, 5, or 10 μM α (as indicated) were electrophoresed on 7.5% nondenaturing gels, dried, and exposed to film. (B) Addition of increasing amounts of NusA to a constant amount of α results in increased complex formation. Reactions containing ³²P-labeled nut-site RNA and various combinations of 9 μM α and 3.5, 7, or 14 μM NusA (as indicated) were electrophoresed on 7.5% nondenaturing gels, dried, and exposed to film. (C) α-CTD stimulates RNA binding by NusA. Reactions containing ³²P-labeled nut-site RNA and various combinations of 13 μM NusA or NusA (amino acids 1–416), 4.5 or 9 μM α, 4.5 or 9 μM α-CTD or 11 μM α-NTD (as indicated) were electrophoresed on 7.5% nondenaturing gels, dried, and exposed to film.