Mitochondrial ribosomes of yeast: isolation of individual proteins and N-terminal sequencing.

Proteins of the small and large subunits of mitochondrial ribosomes from the yeast Saccharomyces cerevisiae were isolated and characterized by two-dimensional gel electrophoresis. Ribosomal proteins of the large subunit were separated by reverse-phase HPLC and up to 37 amino acid residues of the N-terminal sequences of L3, L4, L9 and L31 were determined. No significant homology to ribosomal protein sequences so far determined from other organisms was found.