Substitutions of conserved aromatic amino acid residues in subunit I perturb the metal centers of the Escherichia coli bo-type ubiquinol oxidase.


Cytochrome bo is a four-subunit quinol oxidase in the aerobic respiratory chain of Escherichia coli and functions as a redox-coupled proton pump. Subunit I binds all the redox metal centers, low-spin heme b, high-spin heme o, and CuB, whose axial ligands have been identified to be six invariant histidines. This work explored the possible roles of the… (More)