FIG. 8.

RNA recognition residues of A-VP1. Partial ribbon representation of A-VP1 (PDB no. 2R7R), revealing residues (colored element sticks, labeled) that engage the 3′CS (UGUGACC) of group A +RNA. For simplicity, the nucleotides of the RNA are numbered 1 to 7 in the 3′-to-5′ direction (i.e., C1, C2, A3, etc.). The image includes portions of the finger (pale blue), palm (purple), and thumb (green) subdomains and the N-terminal domain (yellow). Motifs B and F are labeled, and hydrogen bonds are red. Residues N186, K188, R190, F416, R701, and G702 are involved in specific recognition of the UGUG nucleotides. Residues lining the template entry tunnel (S398, S401, T418, K419, K420, G592, E593, K594, and K597) anchor the ribose-phosphate backbone of the RNA. For a stereo image, see Fig. S4 in the supplemental material.