title: Disruption of the MRP-L23 gene encoding the mitochondrial ribosomal protein L23 is lethal for Kluyveromyces lactis but not for Saccharomyces cerevisiae.
abstract: The Kluyveromyces lactis nuclear gene, MRP-L23, encodes a polypeptide of 155 amino acids that shares 70% and 43% identity to the ribosomal proteins L23 and L13 of Saccharomyces cerevisiae and Escherichia coli. The deduced protein, designated K1L23, is a likely component of the large subunit of mitochondrial ribosomes as it can complement the respiratory deficient phenotype of a S. cerevisiae mrp-L23 mutant. As in S. cerevisiae, KlMRP-L23 is essential for respiratory growth of K. lactis because disruption of the gene in a "petite-positive" strain carrying a rho o-lethality suppressor atp mutation rendered cells unable to grow on a nonfermentable carbon source. However, in contrast to S. cerevisiae, disruption of MRP-L23 in wild type K. lactis is lethal. Meiotic segregants of K. lactis with a disrupted MRP-L23 allele form microcolonies with cell numbers varying from 32 to 300. These data clearly indicate an essential role of mitochondrial protein synthesis for viability of the petite-negative yeast K. lactis.
authors.affiliation: Molecular and Cellular Genetics Group, Research School of Biological Sciences, Australian National University, Australia.
authors.forename: G L
authors.initials: GL
authors.lastname: Murray
authors.forename: W G
authors.initials: WG
authors.lastname: Bao
authors.forename: H
authors.initials: H
authors.lastname: Fukuhara
authors.forename: X M
authors.initials: XM
authors.lastname: Zuo
authors.forename: G D
authors.initials: GD
authors.lastname: Clark-Walker
authors.forename: X J
authors.initials: XJ
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D001692:Biological Transport; D002455:Cell Division / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D029968:Escherichia coli Proteins; D005800:Genes, Fungal / Q000235:genetics; D005804:Genes, Lethal / Q000235:genetics*; D005816:Genetic Complementation Test; D049452:Green Fluorescent Proteins; D007716:Kluyveromyces / Q000235:genetics* / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D016296:Mutagenesis; D009154:Mutation; D010641:Phenotype; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D013172:Spores, Fungal / Q000166:cytology / Q000235:genetics
chemical_list: D004271:DNA, Fungal; D029968:Escherichia coli Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D012269:Ribosomal Proteins; C043816:ribosomal protein L23, E coli; D049452:Green Fluorescent Proteins