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. 242 (1988) 4-8] as screening probes. MRP-L4 is located on chromosome XII and codes for a slightly basic protein of 319 aa. The first 14 aa have not been found in the mature protein, and putatively form a signal peptide that is cleaved off during or after mt import. YmL4 has an N terminus very rich in Pro residues, and at its C terminus contains four hydrophobic domains. YmL4 shows no significant sequence similarity to any other sequence from the databases. Gene disruption shows the MRP-L4 product to be indispensable for mt function in cells growing on non-fermentable carbon sources. In contrast to nearly all other MRPs investigated so far, gene disruption of MRP-L4 also affects growth of yeast cells on fermentable carbon sources, suggesting additional cytosolic and/or mt functions of YmL4 besides its involvement in mt protein biosynthesis.
Graack
H R
HR
Institut für Genetik, Freie Universität Berlin, Germany.
Grohmann
L
L
Kitakawa
M
M
Goldschmidt-Reisin
S
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D002451:Cell Compartmentation; D015825:Chromosomes, Fungal; D003001:Cloning, Molecular; D005800:Genes, Fungal / Q000235:genetics*; D005804:Genes, Lethal / Q000235:genetics*; D008928:Mitochondria / Q000737:chemistry*; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D021382:Protein Sorting Signals / Q000235:genetics; D012269:Ribosomal Proteins / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
C091641:MRPL4 protein, S cerevisiae; D024101:Mitochondrial Proteins; D021382:Protein Sorting Signals; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins