Tag-mediated isolation of yeast mitochondrial ribosome and mass spectrometric identification of its new components

Eur J Biochem. 2002 Nov;269(21):5203-14. doi: 10.1046/j.1432-1033.2002.03226.x.


Mitochondrial ribosomal proteins (mrps) of the budding yeast, Saccharomyces cerevisiae, have been extensively characterized genetically and biochemically. However, the list of the genes encoding individual mrps is still not complete and quite a few of the mrps are only predicted from their similarity to bacterial ribosomal proteins. We have constructed a yeast strain in which one of the small subunit proteins, termed Mrp4, was tagged with S-peptide and used for affinity purification of mitochondrial ribosome. Mass spectrometric analysis of the isolated proteins detected most of the small subunit mrps which were previously identified or predicted and about half of the large subunit mrps. In addition, several proteins of unknown function were identified. To confirm their identity further, we added tags to these proteins and analyzed their localization in subcellular fractions. Thus, we have newly established Ymr158w (MrpS8), Ypl013c (MrpS16), Ymr188c (MrpS17) and Ygr165w (MrpS35) as small subunit mrps and Img1, Img2, Ydr116c (MrpL1), Ynl177c (MrpL22), Ynr022c (MrpL50) and Ypr100w (MrpL51) as large subunit mrps.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Macromolecular Substances
  • Mass Spectrometry
  • Mitochondria / chemistry*
  • Mitochondrial Proteins
  • Molecular Sequence Data
  • Multidrug Resistance-Associated Proteins*
  • Ribosomal Proteins / chemistry*
  • Ribosomal Proteins / genetics
  • Ribosomal Proteins / isolation & purification
  • Ribosomal Proteins / metabolism
  • Ribosomes / chemistry*
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / isolation & purification
  • Sequence Homology, Amino Acid


  • MRP4 protein, S cerevisiae
  • Macromolecular Substances
  • Mitochondrial Proteins
  • Multidrug Resistance-Associated Proteins
  • Ribosomal Proteins
  • Saccharomyces cerevisiae Proteins