Phosphatase Docking Modeled

Cdc25 phosphatases are promising targets for anticancer drugs, but it has been difficult to find small-molecule inhibitors that block their interactions with their protein substrates. That's in part because 3-D structures of Cdc25-substrate complexes have so far been impossible to obtain. Now, biochemist Johannes Rudolph of Duke University and coworkers have found a way around the problem (Biochemistry 2005, 44, 16563). They used a computational approach to develop a model for the probable docking orientation of a Cdc25 phosphatase with its substrate, a complex of cyclin-dependent kinase 2 (Cdk2) and cyclin A (CycA). The model (shown), which they have verified by experimentation, reveals "hot spots," sites of specific protein-protein contact to which drugs might be directed. "Our results raise new possibilities for the screening or design of specific inhibitors of this protein-protein interaction" to identify possible anticancer agents, the researchers note.