Structural biology of cell-cycle proteins

The master regulators of the eukaryotic cell cycle are cyclin-dependent protein kinases (CDKs), a highly conserved but functionally diverse enzyme family that also has essential roles in transcription, neuronal physiology, differentiation and apoptosis. CDK-containing complexes drive cell-cycle events and, as the targets of checkpoint pathways, integrate signals to ensure appropriate cell-cycle progression. X-ray crystallography has provided a detailed understanding of the mechanisms by which CDK activity is regulated. Recently reported structures have provided insights into how the protein assemblies that mediate the specific degradation of CDK regulatory proteins function and how checkpoint pathways integrate with the cell cycle.