New sequence data enable modelling of the fungal alternative oxidase and explain an absence of regulation by pyruvate

FEBS Letters

Joseph-Horne, Tim¹  Babij, Joanna²  Sessions, Richard B¹  Wood, Paul M¹  Hollomon, Derek² 

[1] Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, UK;IACR-Long Ashton Research Station, Department of Agricultural Sciences, University of Bristol, Long Ashton, Bristol BS41 9AF, UK

关键词: Fungal alternative oxidase;    Mitochondrial electron transport;    Pyruvate regulation;    Molecular modelling;    Magnaporthe grisea;   

DOI  :  10.1016/S0014-5793(00)01943-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Respiratory rates involving the alternative oxidase (AO) were studied in mitochondria from Tapesia acuformis. There was no evidence for regulation by pyruvate, in contrast with plant AO. The site of interaction of pyruvate with the plant AO is a conserved cysteine. The primary sequence was obtained for AO from Magnaporthe grisea and compared with four published sequences for fungal AO. In all cases this cysteine was absent. Sequence data were obtained for the C-terminal domain of a further five fungal AOs. In this region the fungal sequences were all consistent with a four-helix, di-iron binding structure as in the ferritin-fold family. A molecular model of this domain was deduced from the structure of Δ-9 desaturase. This is in general agreement with that developed for plant AOs, despite very low sequence identity between the two kingdoms. Further modelling indicated an appropriate active site for binding of ubiquinol, required in the AO redox reaction.

【 授权许可】

Unknown