(A) Protein-concentration-dependence. Radiolabelled RNA (5 ng/20 μl) was used with protein concentrations (μg/20 μl) given along each lane. The lower arrow indicates the location of the band without any proteins, and the two higher arrows show the mobility-shifted RNA. (B) and (C) Competition of various unlabelled RNA fragments with radiolabelled 2B1 (5 ng/20 μl) for mobility shift by protein from LVM nuclear extracts (2 μg/20 μl). R, radiolabelled RNA alone; RP, radiolabelled RNA+protein, but no unlabelled RNA. Protein was included in all the lanes with radiolabelled RNA plus different amounts of unlabelled RNA (ng/20 μl, shown with each panel). Arrows indicate the position of the radiolabelled RNA in the absence or the presence of the proteins from the nuclear extracts. (D) G3PDH RNA. R, radiolabelled RNA alone; RP, radiolabelled RNA+protein (1 μg/20 μl).