Structural basis of cyclin-dependent kinase activation by phosphorylation.Russo, A.A., Jeffrey, P.D., Pavletich, N.P.
(1996) Nat Struct Biol 3: 696-700
- PubMed: 8756328
- DOI: https://doi.org/10.1038/nsb0896-696
- Primary Citation of Related Structures:
- PubMed Abstract:
Cyclin-dependent kinase (CDK)-cyclin complexes require phosphorylation on the CDK subunit for full activation of their Ser/Thr protein kinase activity. The crystal structure of the phosphorylated CDK2-CyclinA-ATP gamma S complex has been determined at 2.6 A resolution. The phosphate group, which is on the regulatory T-loop of CDK2, is mostly buried, its charge being neutralized by three Arg side chains. The arginines help extend the influence of the phosphate group through a network of hydrogen bonds to both CDK2 and cyclinA. Comparison with the unphosphorylated CDK2-CyclinA complex shows that the T-loop moves by as much as 7 A, and this affects the putative substrate binding site as well as resulting in additional CDK2-CyclinA contacts. The phosphate group thus acts as a major organizing centre in the CDK2-CyclinA complex.
Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.