Figure 2.

Interaction of ω₂ protein with DNA containing two to four heptads in different orientations. The 59 [(A–C) two heptads], 66 [(D and E) three heptads] and 73 bp [(F–H) four heptads] [α-³²P]HindIII–KpnI DNA (2 nM) and 1 µg of poly[d(I-C)], as non-specific competitor DNA, were incubated with increasing concentrations of ω₂ in buffer B for 15 min at 37°C. The formed ω₂–DNA complexes were analyzed by EMSA. The arrows at the top of the gels indicate number and orientation of the 7 bp repeats. An arrowhead or a bracket to the right of the bands indicates the type(s) of ω₂–DNA complexes. A broken line indicates the position of the fastest moving complexes, detected at low protein concentration. Except in (C), the ω₂ protein concentrations were 4, 8, 16, 32, 64 and 128 nM (lanes 2–7, respectively). In (C) the ω₂ concentrations were 8, 16, 32, 64, 128 and 256 nM. The symbol – in lane 1 indicates the absence of protein, FD labels the band due to free DNA.