Patent ID: 7148044

Claim:
A nucleic acid enzyme capable of recognizing and cleaving a nucleic acid substrate, said nucleic acid enzyme which when bound to the substrate comprises: (i) a first nucleotide sequence 5′-G 1 G 2 G 3 U 4 C 5 C 6 A 13 C 14 C 15 UC 16 C 17 UCGCG 15 G 14 U 13 N 1 N 2 N 3 N 4 N 5 N 6 N 7 G 17 G 16 G 7 C 8 A 9 U 10 G 11 C 12 S 1 B 1 Y-3′ (SEQ ID NO: 65); and (ii) a second nucleotide sequence 5′-B 2 KS 2 G 12 C 11 A 10 U 9 G 8 G 7 CUAAGG 6 G 5 A 4 C 3 C 2 C 1 -3′ (SEQ ID NO: 66); wherein non-variable nucleotides having the same superscript form conventional Watson-Crick base pairs, except the two G 7 form a homopurine base pair; S 1 and S2 are each independently selected from the group consisting of G and C; B 1 and B 2 are each independently selected from the group consisting of G, C, U and T; K is selected from the group consisting of G, U and T; Y is selected from the group consisting of C, U and T; S 1 and S 2 form a conventional Watson-Crick base pair; Y and B 2 may form a conventional Watson-Crick base pair; B 1 and K may form a conventional Watson-Crick base pair; B 1 , K, Y and B 2 may together form a loop; N 1 N 2 N 3 N 4 N 5 N 6 N 7 forms a substrate binding region; N 1 , N 2 , N 3 , N 4 , N 5 and N 6 are each a nucleotide which may be the same or different; N 7 is U; N 7 is capable of forming a wobble pair with the substrate; N 1 , N 2 , N 3 , N 5 and N 6 are capable of forming conventional Watson-Crick base pairs with the substrate; and N 4 is capable of forming a non-conventional Watson-Crick base pair and a conventional Watson-Crick base pair.