title: The tRNA N2,N2-dimethylguanosine-26 methyltransferase encoded by gene trm1 increases efficiency of suppression of an ochre codon in Schizosaccharomyces pombe.
abstract: In the majority of eukaryotic tRNAs, the guanosine at position 26 is modified by a dimethyl group, but so far a function of this modification has not been detected. We isolated the Schizosaccharomyces pombe gene, trm1, encoding the tRNA N2, N2-dimethylguanosine-26 methyltransferase. Strains having the gene deleted completely lack N2,N2-dimethylguanosine. In strains carrying the weak ochre tRNA suppressor sup3-i, deletion of trm1 abolishes suppression indicating that the trm1 deletion acts as an antisuppressor mutation. The result suggests that in vivo N2, N2-dimethylguanosine-26 increases the capacity of the sup3-i serine tRNA to translate the UAA (ochre) codon.
authors.affiliation: Institute of General Microbiology, Baltzerstrasse 4, CH-3012, Bern, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Niederberger
authors.forename: R
authors.initials: R
authors.lastname: Gräub
authors.forename: A
authors.initials: A
authors.lastname: Costa
authors.forename: J
authors.initials: J
authors.lastname: Desgrès
authors.forename: M E
authors.initials: ME
authors.lastname: Schweingruber
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D018389:Codon, Nonsense; D015723:Gene Library; D016153:Genes, Suppressor; D005838:Genotype; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016296:Mutagenesis; D012343:RNA, Transfer / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D012568:Schizosaccharomyces / Q000201:enzymology / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D012359:tRNA Methyltransferases / Q000235:genetics / Q000502:physiology*
chemical_list: D018389:Codon, Nonsense; D012343:RNA, Transfer; C089041:N(2),N(2)-dimethylguanosine-26-methyltransferase; D012359:tRNA Methyltransferases