Minireview Mitochondrial assembly in yeast

The yeast Saccharomyces cerevisiae is likely to be the first organism for which a complete inventory of mitochondrial proteins and their functions can be drawn up. A survey of the 340 or so proteins currently known to be localised in yeast mitochondria reveals the considerable investment required to maintain the organelle's own genetic system, which itself contributes seven key components of the electron transport chain. Translation and respiratory complex assembly are particularly expensive processes, together requiring around 150 of the proteins so far known. Recent developments in both areas are reviewed and approaches to the identification of novel mitochondrial proteins are discussed. z 1999 Federation of European Biochemical Societies. of respiratory chain components are viable and that levels of these components can be manipulated simply by changes in culture conditions. The availability of full genomic sequence data greatly facilitates the characterisation of mutations in genes involved in mitochondrial function or assembly, the identi¢cation of novel mitochondrial proteins and the ge- nome-wide study of changes in gene expression. It is therefore highly likely that yeast will be the ¢rst organism for which a complete inventory of mitochondrial proteins and their func-