Fig. 6.

Helicase activity of UvrD and UvrD_1–647 on various substrates under “low salt” conditions (50 mM KCl). The reactions were started by adding ATP to mixtures containing 2 nM labelled DNA substrate and the indicated concentrations of UvrD and UvrD_1–647. Reactions were incubated for 10 min at 37 °C then terminated and analysed as in Fig. 4. The substrates analysed were: (A) a 3′ single-strand tailed substrate; (B) a blunt-ended 22 bp duplex; (C) a blunt-ended nicked 50 bp duplex. Each substrate contained a 5′ γ-³²P-labelled 22mer, and the label is indicated by an asterisk. The data in the histograms are the average of 3 independent experiments, with standard deviation.