The predicted CCHFV-RdRp active site and positively charged tunnels. (A) The arrangement of structurally conserved RdRp motifs in CCHFV-RdRp model colored yellow, dogged blue, orchid, brown, green and orange for motifs A-F respectively, and superimposed on L1750 (sea green). (B) The corresponding predicted binding site residues are aligned through multiple structure alignment in corresponding motifs. Superposition of the polio virus elongation complex structure (PDB: 3OL8) and foot-and-mouth disease virus in complex with RTP (PDB: 2E9R) shows the positions of the catalytic divalent cations (black spheres) and RTP (salmon) (C) The CCHFV-RdRp model is shown (in ribbon) with four predicted positively charged tunnels (red) marked with arrows as entrance (template and NTP entry channel) and exit (template and nascent strand exit channel) tunnels calculated with MOLE2.0. The domains are same as colored in Fig. 1A. (D) The same representation as (C) for L1750 (PDB: 5 amq) with the 5′ and 3′ vRNA is highlighted. Domain colors are same as in Fig. 1A.