Figure 7. Small molecules bind to clusters of aromatic residues with the D2 sub-domain of p27-KID.

(a) The amino acid sequence of p27-D2 showing sub-domain D2 and the individual small molecule binding regions (labeled D2.1, D2.2 and D2.3). The aromatic amino acids within these regions are illustrated in bold. These represent eight of the nine aromatic residues within p27-KID. (b,c) Average ¹H chemical shift perturbation values for all Group 1 (b) and Group 2 (c) compounds illustrating preferences for interactions with Y (b) and W and Y (c) residues, respectively.