Fig. 14.

Interactions of 5C1:2C2 with selected MANT- and TNP-nucleotides. 5C1, green; 2C2, cyan; heteroatom colors: N, blue; O, red; P, orange; Mn²⁺, violet. Nucleobase-2C2 hydrogen bonds are drawn as red dashed lines, contacting amino acids (distance < 3.5 Å) and secondary structure elements are labeled. (A) Binding mode of 3′-MANT-GTP, model based on the crystal structure PDB 1TL7 (Mou et al., 2005) C and selected H atoms of 3′-MANT-GTP, gray. (B) Binding mode of TNP-ATP, model based on the crystal structure PDB 2GVD (Mou et al., 2006), C and selected H atoms of TNP-ATP, mauve. The gray shadow image shows 3′-MANT-GTP from a superposition of both binding sites (root-mean-square deviation of Cα atoms, 0.44 Å).