Characterization of a yeast mitochondrial ribosomal protein structurally related to the mammalian 68-kDa high affinity laminin receptor.
We have cloned the nuclear gene MRP4 coding for a mitochondrial ribosomal protein of the yeast, Saccharomyces cerevisiae. The gene was isolated by complementation of a respiratory-deficient mutant with a pleiotropic defect in mitochondrial gene expression. The nucleotide sequence of MRP4 revealed that it has sequence similarity with Escherichia coli ribosomal protein S2 and related proteins of chloroplast ribosomes from different plants. Further characterization of the MRP4 protein revealed that it is a component of the 37 S subunit of mitochondrial ribosomes. Moreover, the phenotype of cells carrying a disrupted copy of MRP4 is consistent with the MRP4 protein being an essential component of the mitochondrial protein synthetic machinery. Finally, we note that the MRP4 protein and other members of the S2 family of ribosomal proteins have regions of sequence similarity with the mammalian 68-kDa high affinity laminin receptor.
Davis
S C
SC
Department of Biochemistry, University of Louisville, Kentucky 40292.
Tzagoloff
A
A
Ellis
S R
SR
D000595:Amino Acid Sequence; D001483:Base Sequence; D005800:Genes, Fungal; D005838:Genotype; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D008970:Molecular Weight; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D010641:Phenotype; D011971:Receptors, Immunologic / Q000378:metabolism*; D017474:Receptors, Laminin; D015183:Restriction Mapping; D012269:Ribosomal Proteins / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid
D024101:Mitochondrial Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D011971:Receptors, Immunologic; D017474:Receptors, Laminin; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C489541:MRP4 protein, S cerevisiae; C030004:ribosomal protein S2