Comparison of ubiquinol and cytochrome c terminal oxidases. An alternative view.
There have been numerous instances in the recent literature where the properties of ubiquinol and cytochrome c terminal oxidases are compared. Here we specifically examine the cytochrome bo3-type ubiquinol oxidase from Escherichia coli and the cytochrome aa3-type cytochrome c oxidases. A second redox-active copper site (CuA) is present only in the cytochrome c oxidases and the physiological electron donors for the two enzymes are different (ubiquinol-8 vs. ferrocytochrome c). In our opinion, these differences are significant and most likely indicate that distinct turnover mechanisms are operative in the two enzymes.
Musser
S M
SM
Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena 91125.
Stowell
M H
MH
Chan
S I
SI
D001419:Bacteria / Q000201:enzymology; D001665:Binding Sites; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000737:chemistry / Q000378:metabolism*; D017494:Proton Pumps; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D017494:Proton Pumps; C038862:cytochrome o oxidase; D003576:Electron Transport Complex IV