Figure 3 - full size

Figure 3.
FIGURE 3. Divalent ion binding site in WNV POL. Stereo view of the calcium/magnesium ion non-catalytic binding site. The POL2 model is represented in green sticks and the corresponding electronic density in blue. The Ca^2+ ion is shown as a green sphere. The figure is centered on the aspartic acids of motifs A and C colored in yellow. Coordination with Asp^536 (motif A) and Asp^669 (motif C) are indicated by black dotted lines. Corresponding aspartic acids of motifs A and C in Phi6 (Asp^324, Asp^453, and Asp^454) (PDB code 1HI0) are represented in magenta sticks. The position of the two ions in the catalytic position, inferred from the Phi6 RdRp structure, is indicated in purple.