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.
Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena 91125.
S M
SM
Musser
M H
MH
Stowell
S I
SI
Chan
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