LAUSR

One powerful strategy of how to increase the complexity of cellular proteomes is through post-translational modifications (PTMs) of proteins. Currently there are approximately 400 types of PTMs, the different combinations of which yield a large variety of protein isoforms with distinct biochemical properties. Although mitochondrial proteins undergoing PTMs were identified nearly six decades ago, studies on the roles and extent of PTMs on mitochondrial functions lagged behind the other cellular compartments. The application of mass spectrometry for the characterization of the mitochondrial proteome as well as for the detection of various PTMs resulted in the identification of thousands of amino acid positions that can be modified by different chemical groups. However, the data on mitochondrial PTMs are scattered in several datasets, and the available databases do not contain a complete list of modified residues. To integrate information on PTMs of the mitochondrial proteome of the yeast Saccharomyces cerevisiae, we built the y-mtPTM (Yeast Mitochondrial Post-Translational Modification) Database (http://compbio.fmph.uniba.sk/y-mtptm/). It lists nearly 20,000 positions on mitochondrial proteins affected by approximately twenty various PTMs, with phosphorylated, succinylated, acetylated and ubiquitylated sites being the most abundant. A simple search of a protein of interest reveals the modified amino acid residues, their position within the primary sequence as well as on its 3D structure and links to the source reference(s). The database will serve yeast mitochondrial researchers as a comprehensive platform to investigate the functional significance of the PTMs of mitochondrial proteins.