1. Crystal structure of cdk2, cyclin A-cdk2, and cyclin A-cdk2-p27 complexes. A, The structure of monomeric cdk2. The T-loop is indicated in yellow, and the PSTAIRE motif in red. An ATP molecule in indicated within the active site. B, The structure of cdk2 bound to an amino-terminal truncated version of cyclin A. Cyclin binding re-orients the PSTAIRE helix and moves the T-loop, resulting in the re-positioning of ATP-phosphate groups within the complex and allowing substrate accessibility to the active site. C, The structure of cdk-activating kinase (CAK)-phosphorylated cyclin A bound to cdk2. The yellow ball indicates the position of thr160 within the T-loop. D, The structure of a ternary complex of the amino terminus of p27 bound to cyclin A -cdk2. Separate domains of P27 interact with both cyclin A and cdk2. The structure of this complex reveals that p27 inhibits cdk activity by distorting the structure of the active site, and by binding within the catalytic cleft and preventing ATP binding.
Source: Cell Cycle Control: An Overview, The Online Metabolic and Molecular Bases of Inherited Disease
Citation: Valle D, Beaudet AL, Vogelstein B, Kinzler KW, Antonarakis SE, Ballabio A, Gibson K, Mitchell G. The Online Metabolic and Molecular Bases of Inherited Disease; 2014 Available at: Accessed: December 22, 2017
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