Figure 1

Three-dimensional structure representation of Homing endonuclease I-crei complex (1g9y), using display features of the Lithium software package [75]. a) Overall view of the complex where the protein is displayed in ribbon/tube style and the DNA is represented in color-coded ribbons: red for adenine (A), blue for cytosine (C), green for guanine (G), and yellow for thymine (T). b) Water molecule hydrating a negatively-charged amino acid side-chain. c) Water molecule hydrating a DNA phosphate group. d) Water molecule screening the repulsive interaction between an Asp side-chain and a DNA phosphate. e) Water molecule located at the complex interface mediating specific amino acid-base interactions.