Figure 3.

Single-stranded DNA gaps stimulate RarA ATPase activity. The rate of ATP hydrolysis was measured in the presence of RarA (0.5 μM) and gapped DNA hairpin substrates containing two 16 base pair duplexes separated by poly dT gaps of the indicated size and capped by two four-nucleotide hairpins (0.05 μM molecules, 3.6–4.75 μM total nucleotides). The white square represents a ligated closed-circle substrate while black diamonds represent substrates containing a gap ranging from a single nick to 23 nucleotides. Error bars represent one standard deviation from the mean.