title: Identification of a tRNA isopentenyltransferase gene from Arabidopsis thaliana.
abstract: The tRNA of most organisms contain modified adenines called cytokinins. Situated next to the anticodon, they have been shown to influence translational fidelity and efficiency. The enzyme that synthesizes cytokinins on pre-tRNA, tRNA isopentenyltransferase (EC 2.5.1.8), has been studied in micro-organisms like Escherichia coli and SaccharomYces cerevisiae, and the corresponding genes have been cloned. We here report the first cloning and functional characterization of a homologous gene from a plant, Arabidopsis thaliana. Expression in S. cerevisiae showed that the gene can complement the anti-suppressor phenotype of a mutant that lacks MOD5, the intrinsic tRNA isopentenyltransferase gene. This was accompanied by the reintroduction of isopentenyladenosine in the tRNA. The Arabidopsis gene is constitutively expressed in seedling tissues.
authors: Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala.
authors: Anna
authors: A
authors: Golovko
authors: Folke
authors: F
authors: Sitbon
authors: Elisabeth
authors: E
authors: Tillberg
authors: Björn
authors: B
authors: Nicander
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D029701:Saccharomyces cerevisiae Proteins; D019883:Alkyl and Aryl Transferases; C068392:MOD5 protein, S cerevisiae; C023197:tRNA isopentenyltransferase