Fig. 3.

Effect of the 5′-ssDNA tail on the unwinding efficiency of NS3h in the presence of SSB. The unwinding reaction by NS3h was carried out in the presence of SSB using substrates that either possessed the 5′-tail (Table I, 3) or lacked it (Table I, 4). NS3h (200nM) was incubated with 5 nM ss/dsNA substrate in buffer in one syringe, and mixed with equal volume of 10 mM ATP, 2μM E.coli SSB in the same buffer from the other syringe, for the times indicated The fraction of DNA unwound in each case was plotted as a function of reaction time. The 40bp substrate with the 5′-tail was unwound to a greater extent ( ) than the DNA with out the 5′-tail ( ), but with similar DNA unwinding rates in the range of 3.4 – 3.7 bp/s and 2.9 – 3.1 bp/s, respectively.