Mitochondrial complex I from Arabidopsis and rice: orthologs of mammalian and fungal components coupled with plant-specific subunits.
The NADH:ubiquinone oxidoreductase of the mitochondrial respiratory chain is a large multisubunit complex in eukaryotes containing 30-40 different subunits. Analysis of this complex using blue-native gel electrophoresis coupled to tandem mass spectrometry (MS) has identified a series of 30 different proteins from the model dicot plant, Arabidopsis, and 24 different proteins from the model monocot plant, rice. These proteins have been linked back to genes from plant genome sequencing and comparison of this dataset made with predicted orthologs of complex I components in these plants. This analysis reveals that plants contain the series of 14 highly conserved complex I subunits found in other eukaryotic and related prokaryotic enzymes and a small set of 9 proteins widely found in eukaryotic complexes. A significant number of the proteins present in bovine complex I but absent from fungal complex I are also absent from plant complex I and are not encoded in plant genomes. A series of plant-specific nuclear-encoded complex I associated subunits were identified, including a series of ferripyochelin-binding protein-like subunits and a range of small proteins of unknown function. This represents a post-genomic and large-scale analysis of complex I composition in higher plants.
Heazlewood
Joshua L
JL
Plant Molecular Biology Group, Biochemistry and Molecular Biology, School of Biomedical and Chemical Sciences, Faculty of Life and Physical Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley 6009, Western Australia, Australia.
Howell
Katharine A
KA
Millar
A Harvey
AH
D000595:Amino Acid Sequence; D000818:Animals; D029681:Arabidopsis Proteins / Q000737:chemistry*; D017124:Conserved Sequence; D042967:Electron Transport Complex I; D005656:Fungal Proteins / Q000737:chemistry*; D006801:Humans; D013058:Mass Spectrometry; D008928:Mitochondria / Q000201:enzymology*; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry* / Q000302:isolation & purification; D012275:Oryza / Q000201:enzymology*; D010940:Plant Proteins / Q000737:chemistry*; D021122:Protein Subunits
D029681:Arabidopsis Proteins; D005656:Fungal Proteins; D010940:Plant Proteins; D021122:Protein Subunits; D009247:NADH, NADPH Oxidoreductases; D042967:Electron Transport Complex I