ABSTRACT
The protein kinase family encompasses more than three hundred members of critically important enzymes, each one with a specific role or function within the cell. Protein kinases are significant targets for therapeutic drug development and have been implicated as the disease causing components of numerous tumor viruses. The crystallographic analysis of the structural homology of protein kinases can now be carried out using structures of various kinases to find a common search model to be used in molecular replacement methods. Six out of nine invariant residues of the catalytic core of protein kinase are involved in ATP binding and catalysis. Template modeling provides a rational basis for the design of specific inhibitors for protein kinases based on the ATP binding site. Crystallographic analysis has shown that both the substrate and ATP-binding clefts are structurally conserved yet differ in the surface charges between individual protein kinases.
