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Cytochrome oxidase evolved by tinkering with denitrification enzymes
Author(s) -
Saraste Matti,
Castresana Jose
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)80228-9
Subject(s) - cytochrome c oxidase , biochemistry , oxidase test , coenzyme q – cytochrome c reductase , nitrite reductase , electron transport complex iv , cytochrome b , cytochrome , cytochrome p450 reductase , chemistry , respiratory chain , denitrification , denitrifying bacteria , nitrous oxide reductase , biology , cytochrome c , enzyme , mitochondrion , mitochondrial dna , nitrate reductase , gene , organic chemistry , nitrogen
The cytochrome bc complex which is encoded by the fixNOPQ operon in Bradyrhizobiumjaponicum , is the most distant member of the haem‐copper cytochrome oxidase family. We have found that its major subunit, FixN, is homologous to the NorB subunit of nitric oxide reductase in a purple bacterium. A second evolutionary link between cytochrome oxidases and denitrification enzymes is the presence of a similar binuclear copper site in cytochrome aa 3 (the mitochondrial oxidase) and nitrous oxide reductase. This centre was probably acquired by a primitive FixN‐type oxidase, leading to the evolution of the mitochondrial‐type oxidase. These links suggest that the oxygen‐reducing respiratory chain developed from the anaerobic, denitrifying respiratory system.