Figure 3. RNA is preferred to DNA by hEndoV as a substrate.

(a) ³² P-labelled 30-mer ssDNA containing deoxyinosine and/or 21-mer ssRNA containing inosine was incubated with hEndoV (lanes 1, 3 and 5: 0 nM; lane 2: 150 nM; lane 4: 8 nM; and lanes 6–10: 1, 2, 4, 8 and 16 nM). Cleavage sites were analysed by electrophoresis. (b) hEndoV preferentially binds to ssRNA rather than ssDNA. ³²P-labelled 30-mer ssDNA containing deoxyinosine was incubated with hEndoV (lane 1: 0 nM and lanes 2–6: 300 nM) and cold ssRNA containing inosine (lanes 2–6: 0, 2.5, 5.0, 7.5 and 10 μM; left panel). ³² P-labelled 21-mer ssRNA containing inosine was incubated with hEndoV (lane 7: 0 nM and lanes 8–12: 300 nM) and cold ssDNA containing deoxyinosine (lanes 8–12: 0, 2.5, 5.0, 7.5 and 10 μM; right panel). Free and bound fractions were separated on a nondenaturing 8% polyacrylamide gel.