Mitochondrial steps of arginine biosynthesis are conserved in the hydrogenosomes of the chytridiomycete Neocallimastix frontalis.
Arginine biosynthesis in eukaryotes is divided between the mitochondria and the cytosol. The anaerobic chytridiomycete Neocallimastix frontalis contains highly reduced, anaerobic modifications of mitochondria, the hydrogenosomes. Hydrogenosomes also occur in the microaerophilic flagellate Trichomonas vaginalis, which does not produce arginine but uses one of the mitochondrial enzymes, ornithine transcarbamoylase, in a cytosolic arginine dihydrolase pathway for ATP generation. EST sequencing and analysis of the hydrogenosomal proteome of N. frontalis provided evidence for two mitochondrial enzymes of arginine biosynthesis, carbamoylphosphate synthase and ornithine transcarbamoylase, while activities of the arginine dehydrolase pathway enzymes were not detectable in this fungus.
Gelius-Dietrich
Gabriel
G
Institute of Botany III, Heinrich Heine University Duesseldorf, Universitaetsstrasse 1, 40225 Duesseldorf, Germany.
Ter Braak
Michael
M
Henze
Katrin
K
D000595:Amino Acid Sequence; D001120:Arginine / Q000096:biosynthesis*; D002222:Carbamoyl-Phosphate Synthase (Ammonia) / Q000032:analysis / Q000737:chemistry; D018076:DNA, Complementary; D020224:Expressed Sequence Tags; D005656:Fungal Proteins; D015723:Gene Library; D008969:Molecular Sequence Data; D020088:Neocallimastix / Q000201:enzymology / Q000378:metabolism*; D015388:Organelles / Q000737:chemistry / Q000378:metabolism*; D009954:Ornithine Carbamoyltransferase / Q000032:analysis / Q000737:chemistry; D020543:Proteome; D016415:Sequence Alignment
D018076:DNA, Complementary; D005656:Fungal Proteins; D020543:Proteome; D001120:Arginine; D009954:Ornithine Carbamoyltransferase; D002222:Carbamoyl-Phosphate Synthase (Ammonia)