The DbpA catalytic core unwinds double-helix substrates by directly loading on them

(A) Model molecules used to investigate the initiation site of DbpA protein helicase activity. (B) Helicase activity of DbpA in the presence of molecule A:X (filled triangle), A:Y (empty triangle), B:X (circle), C:X (diamond), D:X (empty square), and E:X (filled square). These are representative of the helicase experiments performed in the presence of 600 nM DbpA concentration. The average values and standard deviations for the observed rate constants of unwinding at 100, 300, and 600 nM of DbpA are shown in Table 1.