Figure 1. Postulated H-Channel for proton translocation in bCcO.

The structure was drawn with the PyMol Molecular Graphics System, Schrodinger, LLC. The large voids found near the H-Chanel in the crystal structure of oxidized bCcO (PDB: 3ABL), where water may be stored, are highlighted by the gray surfaces generated by the software “Hollow” [47] with a 1.3 Å sphere.