Allosteric interactions and proton conducting pathways in proton pumping aa3 oxidases: Heme a as a key coupling element

► Characterization of allosteric interactions in proton pumping aa3 oxidases. ► Heme a plays a key role in the proton pump of aa3 oxidases. ► Aminoacid replacement or Zn2 + binding at the negative surface of COV uncouple proton pumping.