FIGURE 11.

Bound K⁺ and Tyr¹²²-hydrophobic cluster in crystal structures. The part of structures (E1∼PCa₂·ADP analog, left) and (E2∼P analog, right) around Y122-HC and the bound K⁺ ion are shown in schematic models (PDB codes: 1T5T and 1XP5 (12, 15)). The two structures were manually aligned with M8–M10 helices, which do not move virtually in the two. K⁺ bound in these structures is shown by a yellow van der Waals sphere. Gln²⁴⁴ on the A/M3-linker at the immediate vicinity of the bound K⁺ in is indicated by ball and stick model.