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. |