Figure 1.

Structure of the full-length HPr protein kinase from Staphylococcus xylosus. (A) Front view of the HPrK hexamer, composed of three structurally identical dimers deeply intertwined. The kinase domains (HPrK_C) occupy the central part of the structure whereas the N-terminal domains (HPrK_N) extend outwards as pairwise blades in a propeller. Phosphate ions in the interface between N-terminal domains and P-loop regions are depicted as CPK models. (B) Side view of the hexamer. (C) Stereo view of the HPrK dimer representing the asymmetric unit of the crystal.