Figure 3.

Overall Structure of Tm-RNase H2 Substrate Complex, Two Views

The two domains are color coded (N-terminal domain in purple for β strands and orange for the rest of the structure and the C-terminal domain in yellow). The mobile loop (including the DSK motif) is indicated with an arrow. Nucleic acid is shown in cartoon representation with DNA in blue and the single ribonucleotide in red. Nucleic acid residues at positions +1 and +2 (the [5′]RNA-DNA[3′] junction) are shown as sticks. Active site residues are shown in orange ball and sticks and the tyrosine 163 interacting with the 2′-OH group of the ribonucleotide at the junction in yellow. Calcium ions are shown as green spheres.