Mitochondrial Genomics and Proteomics of Yarrowia lipolytica

In recent years, we have developed the obligate aerobic yeast Y. lipolytica as a model system to analyse respiratory chain complex I (proton pumping NADH:ubiquinone oxidoreductase). Our studies were aimed at exploring structural and functional constraints for the reaction mechanism at the catalytic core of this giant enzyme, defined as the site where ubiquinone reduction couples to proton translocation. Extensive genomic and proteomic analyses of Y. lipolytica mitochondria resulted in the discovery of 41 different complex I subunits, encoded both by the mitochondrial and the nuclear genome. Most of the subunits of complex V (ATP synthase) and a protein specifically involved in complex I iron–sulfur cluster assembly were also described. Novel gel-electrophoretic separation techniques and analytical methods, especially laser-induced liquid bead ion desorption (LILBID) mass spectrometry, developed for these purposes, have great potential as useful tools for obtaining molecular fingerprints of large protein assemblies.