Fig 4.

Comparison of the N3 380-loop in with distinct NA structures. (A) Location of the 380-loop, 320-loop, and 330-loop in VN04N1 (orange), N2 (blue), and N3 (yellow). The distance between the 380-loop and 320-loop in N3 is the greatest. (B to D) Residues 319 and 320 form hydrogen bonds with the 380-loop in N1, N2, and N3. The 380-loop in N1 and N2 forms more hydrogen bonds with the 320-loop and adjacent residues relative to N3. Residues that take part in hydrogen bonds between and among the 380-loop, 320-loop, and 330-loop are labeled. Residues that are marked with an asterisk (*) indicate that they only take part in hydrogen bonds via their main chain oxygen or nitrogen.