Mammalian mitochondrial ribosomal proteins. N-terminal amino acid sequencing, characterization, and identification of corresponding gene sequences.

The integrity of healthy mitochondria is supposed to depend largely on proper mitochondrial protein biosynthesis. Mitochondrial ribosomal proteins (MRPs) are directly involved in this process. To identify mammalian mitochondrial ribosomal proteins and their corresponding genes, we purified mature rat MRPs and determined 12 different N-terminal amino acid sequences.

Identification and characterization of the genes for mitochondrial ribosomal proteins of Saccharomyces cerevisiae.

We have purified 13 large subunit proteins of the mitochondrial ribosome of the yeast Saccharomyces cerevisiae and determined their partial amino acid sequences. To elucidate the structure and function of these proteins, we searched for their genes by comparing our sequence data with those deduced from the genomic nucleotide sequence data of S. cerevisiae and analyzed them.

Gene MRP-L4, encoding mitochondrial ribosomal protein YmL4, is indispensable for proper non-respiratory cell functions in yeast.

In order to characterize individual protein components of the mitochondrial (mt) ribosome for regulatory, functional and evolutionary studies, the yeast nuclear gene MRP-L4 (accession No. Z30582), coding for the mt ribosomal protein (MRP) YmL4, has been cloned using oligodeoxyribonucleotides (oligos) deduced from a partial amino acid (aa) sequence [Graack et al., FEBS Lett.

The yeast nuclear gene MRP-L13 codes for a protein of the large subunit of the mitochondrial ribosome.

The nuclear gene MRP-L13 of Saccharomyces cerevisiae, which codes for the mitochondrial ribosomal protein YmL13, has been cloned and characterized. It is a single-copy gene residing on chromosome XI. Its nucleotide sequence was found to be identical to that of the previously reported ORF YK105.

Extended N-terminal sequencing of proteins of the large ribosomal subunit from yeast mitochondria.

We have determined the N-termini of 26 proteins of the large ribosomal subunit from yeast mitochondria by direct amino acid micro-sequencing. The N-terminal sequences of proteins YmL33 and YmL38 showed a significant similarity to eubacterial ribosomal (r-) proteins L30 and L14, respectively. In addition, several proteins could be assigned to their corresponding yeast nuclear genes.