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Structure and evolution of cytochrome oxidase
1European Molecular Biology Laboratory, Heidelberg, Germany.
Antonie Van Leeuwenhoek
|January 1, 1994
Summary
Cytochrome oxidases evolved unique copper centers (CuA) for substrate specificity. Primitive forms and some quinol oxidases lack CuA, suggesting an earlier evolutionary path related to nitric oxide reductase.
Area of Science:
- Biochemistry
- Evolutionary Biology
- Microbiology
Background:
- Cytochrome oxidases are crucial enzymes in cellular respiration.
- Their structural diversity reflects varied evolutionary adaptations and substrate specificities.
Purpose of the Study:
- To review the structural evolution of cytochrome oxidases.
- To correlate structural features, particularly the copper center (CuA), with enzyme function and evolutionary history.
Main Methods:
- Comparative structural analysis of various cytochrome oxidases.
- Review of existing literature on enzyme evolution and function.
Main Results:
- Cytochrome c oxidases possess a unique copper center (CuA), absent in quinol oxidases.
- Quinol oxidases have independently lost CuA during evolution.
- Primitive cytochrome c oxidases lack CuA, utilizing c-type hemes for electron entry.
- The rhizobial FixN complex exemplifies these primitive oxidases, related to nitric oxide reductase.
Conclusions:
- The presence or absence of CuA is a key indicator of evolutionary lineage and substrate specificity in cytochrome oxidases.
- Primitive oxidases, lacking CuA, likely represent an ancestral form linked to denitrification pathways.