Review article: structural and functional properties of cytochrome aa3 from bacteria.

The aa3 oxidases from bacteria form a group of related enzymes that resemble the far more complex mitochondrial cytochrome c oxidase, both functionally and structurally. These enzymes catalyze electron transfer from ferrocytochrome c to oxygen to produce water. This transfer is coupled to proton translocation. Several oxidases of this type have been purified from cytoplasmic membranes of bacteria. This review summarizes the present knowledge on purified bacterial aa3 oxidases and correlates these findings with data available for the eukaryotic cytochrome c-oxidases.