Prediction of the structure of the common perimitochondrial localization signal of nuclear transcripts in yeast

Many nuclear genes encoding mitochondrial proteins require specific localization of their mRNAs to the vicinity of mitochondria for proper expression. Studies in Saccharomyces cerevisiae have shown that the cis-acting signal responsible for subcellular localization of mRNAs is localized in the 3' UTR of the transcript. In this paper we present an in silico approach for prediction of a common perimitochondrial localization signal of nuclear transcripts encoding mitochondrial proteins. We computed a consensus structure for this signal by comparison of 3' UTR models for about 3000 yeast transcripts with known localization. Our studies show a short stem-loop structure which appears in most mRNAs localized to the vicinity of mitochondria. The degree of similarity of a given 3' UTR to our consensus structure strongly correlates with experimentally determined perimitochondrial localization of the mRNA, therefore we believe that the structure we predicted acts as a subcellular localization signal. Since our algorithm operates on structures, it seems to be more reliable than sequence-based algorithms. The good predictive value of our model is supported by statistical analysis.