Figure 5

Model of Tax-CDK4 interaction. A) Map of CDK4 regions relevant for Tax-binding. The N-terminal region of CDK4 is relevant in all binding assays, suggesting that it is the major binding region. In addition, the C-terminus is considered as a second possible binding region. Red: regions, which upon deletion result in reduced binding; green: regions, which bind to Tax. B) Tertiary structure prediction of CDK4. The structure was calculated from the amino acid sequence at Swiss Model http://swissmodel.expasy.org. The resulting pdb file was visualized with rasmol. The prediction shows the proximity of N- and C-terminal regions in the folded CDK4 protein. Thus, it is conceivable that both represent a non-contiguous binding domain for Tax. Red: C-terminal segment; blue:N-terminal segment