The respiratory complex I in yeast: Isolation of a gene NUO51 coding for the nucleotide-binding subunit of NADH : ubiquinone oxidoreductase from the obligately aerobic yeast Yarrowia lipolytica

We have isolated a gene NUO51 coding for a homologue of the nucleotide-bind ing subunit of mitochondrial respiratory chain linked NADH:ubiquinone oxido reductase from the obligately aerobic yeast Yarrowia lipolytica. DNA sequen cing revealed a 1464 bp open reading frame encoding a protein with predicte d molar mass of about 53.7 kDa. The sequence is highly conserved with its c ounterparts from filamentous fungi and represents the first yeast homologue of the NADH-binding subunit (51 kDa) of the respiratory complex I. In addi tion, PFGE and Southern hybridization analysis indicate that NUO51 is a sin gle copy gene in the genome of Y. lipolytica. The expression of NUO51 by No rthern blot analysis was also examined.