Figure 2
An enlarged image of the binding site between the two domains. The image on the left shows the difference density (mFo − DFc, 3σ) before guanine was placed into the model. The relevant amino acids in the binding site are shown and the backbone is coloured by Jones' rainbow as in Fig. 1 (a). The middle and right figures are rotated plus and minus approximately 90° from the figure on the left and are coloured by atom type, with C in cyan, O in red and N in dark blue. Potential hydrogen bonds are represented as black lines; approximate distances between potential hydrogen-bond acceptors and donors are shown in Å and the binding residues are labelled. Note that the Asn218 is out of plane to the guanine, so the hydrogen on the Asn218 N atom is likely to interact with the π-cloud perpendicular to the plane of the atoms. |