Hybrid respiration in the denitrifying mitochondria of Fusarium oxysporum.
Induction of the mitochondrial nitrate-respiration (denitrification) system of the fungus Fusarium oxysporum requires the supply of low levels of oxygen (O(2)). Here we show that O(2) and nitrate (NO(3)(-)) respiration function simultaneously in the mitochondria of fungal cells incubated under hypoxic, denitrifying conditions in which both O(2) and NO(3)(-) act as the terminal electron acceptors. The NO(3)(-) and nitrite (NO(2)(-)) reductases involved in fungal denitrification share the mitochondrial respiratory chain with cytochrome oxidase. F. oxysporum cytochrome c(549) can serve as an electron donor for both NO(2)(-) reductase and cytochrome oxidase. We are the first to demonstrate hybrid respiration in respiring eukaryotic mitochondria.
Takaya
Naoki
N
Institute of Applied Biochemistry, University of Tsukuba, Tsukuba, Ibaraki 305-8572.
Kuwazaki
Seigo
S
Adachi
Yoshiaki
Y
Suzuki
Sawako
S
Kikuchi
Tomoko
T
Nakamura
Hiro
H
Shiro
Yoshitsugu
Y
Shoun
Hirofumi
H
D000818:Animals; D045304:Cytochromes c / Q000378:metabolism; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism; D005670:Fusarium / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D009565:Nitrate Reductases / Q000378:metabolism; D009572:Nitrite Reductases / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D009609:Nitrous Oxide / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D018892:Proton-Motive Force
D009573:Nitrites; D045304:Cytochromes c; D009565:Nitrate Reductases; D009572:Nitrite Reductases; D003576:Electron Transport Complex IV; D009609:Nitrous Oxide; D009584:Nitrogen; D010100:Oxygen