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MRM2 encodes a novel yeast mitochondrial 21S rRNA methyltransferase
Author(s) -
Pintard Lionel,
Bujnicki Janusz M.,
Lapeyre Bruno,
Bonnerot Claire
Publication year - 2002
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/21.5.1139
Subject(s) - biology , peptidyl transferase , ribosomal rna , 23s ribosomal rna , pseudouridine , ribosome , saccharomyces cerevisiae , ribosomal protein , transfer rna , mitochondrial dna , genetics , rna , microbiology and biotechnology , biochemistry , yeast , gene
Mitochondria of the yeast Saccharomyces cerevisiae assemble their ribosomes from ribosomal proteins, encoded by the nuclear genome (with one exception), and rRNAs of 15S and 21S, encoded by the mitochondrial genome. Unlike cytoplasmic rRNA, which is highly modified, mitochondrial rRNA contains only three modified nucleotides: a pseudouridine (Ψ 2918 ) and two 2′‐ O ‐methylated riboses (Gm 2270 and Um 2791 ) located at the peptidyl transferase centre of 21S rRNA. We demonstrate here that the yeast nuclear genome encodes a mitochondrial protein, named Mrm2, which is required for methylating U 2791 of 21S rRNA, both in vivo and in vitro . Deletion of the MRM2 gene causes thermosensitive respiration and leads to rapid loss of mitochondrial DNA. We propose that Mrm2p belongs to a new class of three eukaryotic RNA‐modifying enzymes and is the orthologue of FtsJ/RrmJ, which methylates a nucleotide of the peptidyl transferase centre of Escherichia coli 23S rRNA that is homologous to U 2791 of 21S rRNA. Our data suggest that this universally conserved modified nucleotide plays an important function in vivo , possibly by inducing conformational rearrangement of the peptidyl transferase centre.