Tailoring RNA modular units on a common scaffold: A modular ribozyme with a catalytic unit for β-nicotinamide mononucleotide-activated RNA ligation

(A) Ligation reaction by the YFL-1 variants with different nucleotide combinations between substrate 3′-end (position 1) and position 19. (X) The nucleotide at the 3′-end of the substrate (position-1); (Y) the nucleotide at position 19. (B) Activities of the YFL-1 variants with complementary nucleotides between positions −1 and 19: (filled circles) G–C, (filled squares) C–G, (open circles) A–U, and (open squares) U–A. (C) Relative activities of possible nucleotide combinations between positions −1 and 19. Reactions were carried out for 6 h.