Figure 7.

Binding of the N-terminal constructs α1−917 (panel a) and α1−835 (panel b) shows no stabilization of ssDNA through the sequence of extension/relaxation cycles (in the sequence order blue, green, red), as indicated by the complete reannealing of DNA at high forces upon relaxation in both cases. A slight change in the melting force, indicating some dsDNA binding, is evident for α1−917 but not for α1−835. The strong overlap of the extension curves (solid lines) emphasizes the reproducibility of the data, whereas some variability is evident upon relaxation (dotted lines), though this is typical of these experiments with DNA even in the absence of protein (black).