Molecule of the Month: Cyclin and Cyclin-dependent Kinase
Cyclins and cyclin-dependent kinases control when cells divide, making them important targets for cancer therapy.
Cycles and Checkpoints
Tuning the Cycle
Exploring the Structure
Cyclin-dependent Kinase and Anticancer Drugs
CDK enzymes are targets for cancer chemotherapy, since by blocking them, we can block the abnormal growth of tumor cells. Much effort has been focused on CDK4 and CDK6, which guard a key restriction point before the cell starts DNA replication. Structures of three US FDA-approved drugs are shown here (PDB entries 2euf, 5l2t and 5l2s), all of which were discovered through structure-based design. They all have different chemical structures, but bind in a similar way to the active site of the enzyme, blocking its ability to bind to ATP and phosphorylate target proteins. To compare these structures in more detail, click on the image for an interactive JSmol.
Topics for Further Discussion
- Many structures of other inhibitors with CDK have been determined. Try searching for “CDK inhibitor” in the main RCSB site to explore some of them.
- Kinases often have a two-domain structure, with the active site formed between the two domains. Try comparing the structure of CDK with, for example, the MAP kinase (which is similar and is thought to have evolved from the same ancestral enzyme), or glycolytic phosphoglycerate kinase (which is quite different).
August 2019, David Goodselldoi:10.2210/rcsb_pdb/mom_2019_8