Kristene K. Surerus

Cytochromecaa3 from the thermophilic bacteriumThermus thermophilus: A member of the heme-copper oxidase superfamily

The subject of this short review is the cytochromec oxidase (caa3) from the thermophilic bacteriumThermus thermophilus. First, some of the extensive physical and enzymological results obtained with this enzyme are reviewed, and two experiments are described, involving isotope substitutions in combination with Mössbauer and ENDOR spectroscopies, which have provided novel insight into the active sites of the enzyme. Second, we summarize recent molecular genetic work showing thatThermus cytochromecaa3 is abona fide member of the superfamily of heme-copper oxidases. Finally, we present a rough three-dimensional model and speculate about certain features of the metal-binding sites.

Cytochrome c Oxidase: A Brief Introduction and Some New Results from High Field Endor Studies of The CuA and CuB Sites

A Mitchellian view of mitochondrial respiration is presented in Scheme I.1,2 This illustrates electron transfer from an electron rich material, NH, through quinone, Q, through Complex HI, into cytochrome c, and through Complex IV(cytochrome c oxidase) to O2, with accompanying proton translocations across the lipid bilayer.