Figure 5.

EMSA of RF2a and the 3Δ mutant of RF2a. Oligonucleotides containing the Box IIm_l sequences (10) were used as ³²P-labeled probe or an unlabeled competitor in an EMSA with 500 ng of E. coli protein containing 3Δ or RF2a. Unbound probe is located near the bottom of the gel. The x band in lanes 1, 2, 4, and 5 is presumed to result from binding with an uncharacterized protein from E. coli. Lane 1, protein prepared from E. coli. Lane 2, reaction with extracts of E. coli that produce RF2a. Lane 3, reaction with equimolar amounts of RF2a and 3Δ plus 80× molar excess of unlabeled competitor probe relative to the labeled probe. Lane 4, reaction with equimolar amounts of RF2a and 3Δ. Lane 5, reaction with 3Δ.