THE CDK2 BINDING DOMAIN OF P27(KIP) CORRELATES WITH THE INHIBITION OFTHE KINASE-ACTIVITY OF CDK2 CYCLIN COMPLEXES/

The cyclin-dependent kinase inhibitor p27(Kip) binds to cyclin/cyclin- dependent kinases and preferentially inhibits the catalytic activity o f cdk2 and cdk4. The cdk2 binding domain of p27(Kip) was determined us ing a series of N-terminal truncated and point mutations of GST-p27(Ki p). The binding domain was contained within amino acid residues 53-85. The inhibition of the catalytic activity of preformed functional cdk2 /cyclin complexes by p27(Kip) was also associated with the binding dom ain.