Table 1.

The RecQ helicase can bind to and unwind a wide variety of DNA substrates

DNA substrate	Structure (annealed oligonucleotides)a	Unwinding rateb (nm (bp)/nm RecQ/sec)	Relative binding affinityc
3-way junction		2.9	7
Flayed duplex		2.2	8
5′-ssDNA overhang		1.2	2
3′-ssDNA overhang		1.1	12
4-way junction		1.0	1
63-bp blunt duplex		0.8	N/D
48-bp blunt duplex		0.2	1

Reactions were performed and analyzed as described in Materials and Methods. 

^aNumbers correspond to the oligonucleotides in Table 2 annealed as described in Materials and Methods to form the indicated DNA substrate. 

^bCalculated from the linear slope of a plot of unwinding rate [nm (bp)/sec] vs. RecQ helicase concentration (nm). The relative error for each rate is approximately ±5%. 

^cDetermined as in Materials and Methods and normalized to the binding value of 5 × 10⁶/m obtained for the 48-bp blunt duplex substrate. The relative error for each value is approximately ±5%.