Figure 3.
Figure 3 a, Comparison of the structure of p19^Ink4d closest
to the mean with that of 53BP2. The structures are shown in the
same orientation as those in Fig. 2 and the C carbons
of structurally equivalent residues in ankyrins III and IV from
p19^Ink4d and II and III from p53BP2 have been superimposed. The
surface-exposed residues of the sequence corresponding to the
p16^Ink4a peptide fragment (residues 80-99), previously shown
partially to mimic the activity of the intact protein, are shown
in yellow (ref. 22, and S. Wick, M. Dubay and L.B., unpublished
results). The side chains of residues 91 and 92, which, based on
alanine scanning mutagenesis in the peptide^22, most influence
the interaction with Cdk4 and Cdk6, are shown in dark blue. b,
Protein surfaces of the same p19^Ink4d structure (but now
rotated 55
? about the y-axis compared to that shown in a and Fig. 2) and a
model of Cdk4/cyclin D1 (B.O.S., unpublished). Cdk4 is shown in
white, cyclin D1 in purple, and Lys 22, Arg 24 and residues
95-97 of Cdk4 are in red; a yellow arrow indicates the position
of the active site in Cdk4. These plots were generated using
MOLSCRIPT29 and GRASP30.
carbons
of structurally equivalent residues in ankyrins III and IV from
p19^Ink4d and II and III from p53BP2 have been superimposed. The
surface-exposed residues of the sequence corresponding to the
p16^Ink4a peptide fragment (residues 80-99), previously shown
partially to mimic the activity of the intact protein, are shown
in yellow (ref. 22, and S. Wick, M. Dubay and L.B., unpublished
results). The side chains of residues 91 and 92, which, based on
alanine scanning mutagenesis in the peptide^22, most influence
the interaction with Cdk4 and Cdk6, are shown in dark blue. b,
Protein surfaces of the same p19^Ink4d structure (but now
rotated 
55
? about the y-axis compared to that shown in a and Fig. 2) and a
model of Cdk4/cyclin D1 (B.O.S., unpublished). Cdk4 is shown in
white, cyclin D1 in purple, and Lys 22, Arg 24 and residues
95-97 of Cdk4 are in red; a yellow arrow indicates the position
of the active site in Cdk4. These plots were generated using
MOLSCRIPT29 and GRASP30.