Figure 2.

hEndoV prefers adenine base located at the + 1 position site. (A) ³²P-labeled substrates containing rX (rA, rC, rG, or rU) at the + 1 position. Arrows indicate cleavage positions. Intact 21-nt; Intact oligonucleotide. Product 12-nt; cleavage products. (B) The ³²P-labeled substrate containing rA (lanes 1–4), rC (lanes 5–8), rG (lanes 9–12), and rU (lanes 13–16) were incubated with 5 nM hEndoV at 37 ℃ for indicated time. The cleavage products were analyzed by denaturing 12.5% urea gel electrophoresis. Arrows mark the positions of the intact oligonucleotide (I) and the product (P) after hEndoV endonuclease activity. (C) Graphs showing the yield of the cleavage products obtained from (B) hEndoV cleavage. (D) ³²P-labeled substrates containing rA (lanes 1–4), rC (lanes 5–8), rG (lanes 9–12), and rU (lanes 13–16) were incubated with the indicated concentrations of hEndoV for 30 min. (E) Graphs showing the yield of cleavage products obtained from (D) hEndoV cleavage. Abbreviations: hEndoV, human endonuclease V; P, phosphorus; rA, riboadenine; rC, ribocytosine; rG, riboguanine; rU, ribouracil Representatives of three independent experiments are shown.