Figure 2.
Self-phosphorylating DNAs with distinct substrate specificities. (A) Sequences of nine representative classes of deoxyribozymes. Nucleotides corresponding to the original random-sequence domain are numbered. Underlined nucleotides in dNTP-N1 identify BstN I, EagI and BsmAI sites from left to right. (B) Substrate specificity of individual deoxyribozymes. Filled arrowheads identify internally 32P-labeled precursor DNAs, and open arrowheads identify the positions of the ligated products that are indicative of deoxyribozyme activity. Reaction conditions were as follows: Nucleoside triphosphate concentrations: NTP-A1, U1, C1, N1, and dNTP-C1 and N1 (1 mM); NTP-G1, dNTP-G1, and dNTP-A1 (50 μM). Incubation times: NTP-G1, NTP-A1, and dNTP-G1, A1, and C1 (20 hr); NTP-C1 (46.5 hr), dNTP-N1 (60 hr), NTP-U1 (92.5 hr); NTP-N1 (94 hr).