Fig. 1.

Conserved core of the eukaryotic protein kinases with the 26 preselected key residues (black spheres). The core consists of two lobes: N-lobe and C-lobe. ATP (shown as black sticks) is sandwiched between the lobes bound to two magnesium ions (teal spheres). Two hydrophobic ensembles C-spine (yellow surface) and R-spine (red surface) span the core, providing global connectivity within the molecule. The DFG motif and APE motif are flanking the activation segment (red ribbon). The HRD motif is a part of the catalytic loop (olive ribbon). Both spines are anchored to the αF-helix (dark red) that spans the C-lobe and serves as a foundation for the catalytic machinery of the kinase. Additional description of the selected key residues is provided in the Table 1.