Figure 1.

Design of a 5′-nucleotidyl transferase for N>p’s. (a) Two-way junction HPz, which catalyzes reversible RNA ligation using a 2′,3′-cyclic phosphate. (b) Redesign of HPz into 5NTz. (c) Structural model of the substrate-binding pocket of 5NTz (based on PDB 1M5V(9)). The ribozyme is shown as surface; A>p and the acceptor strand (AS) are shown in stick models. (d) 5NTz catalyzes 5′-adenylation in ice (2 mM A>p, 2 μM 5NTz, 1 μM 3′-FITC-labeled AS, 72 h in ice at −7 °C).