title: Duplication and quadruplication of Arabidopsis thaliana cysteinyl- and asparaginyl-tRNA synthetase genes of organellar origin.
abstract: Two cysteinyl-tRNA synthetases (CysRS) and four asparaginyl-tRNA synthetases (AsnRS) from Arabidopsis thaliana were characterized from genome sequence data, EST sequences, and RACE sequences. For one CysRS and one AsnRS, sequence alignments and prediction programs suggested the presence of an N-terminal organellar targeting peptide. Transient expression of these putative targeting sequences joined to jellyfish green fluorescent protein (GFP) demonstrated that both presequences can efficiently dual-target GFP to mitochondria and plastids. The other CysRS and AsnRSs lack targeting sequences and presumably aminoacylate cytosolic tRNAs. Phylogenetic analysis suggests that the four AsnRSs evolved by repeated duplication of a gene transferred from an ancestral plastid and that the CysRSs also arose by duplication of a transferred organelle gene (possibly mitochondrial). These case histories are the best examples to date of capture of organellar aminoacyl-tRNA synthetases by the cytosolic protein synthesis machinery.
authors.affiliation: Station de Génétique et Amélioration des Plantes, INRA, Route de St Cyr, 78026 Versailles Cedex, France.
authors.forename: N M
authors.initials: NM
authors.lastname: Peeters
authors.forename: A
authors.initials: A
authors.lastname: Chapron
authors.forename: A
authors.initials: A
authors.lastname: Giritch
authors.forename: O
authors.initials: O
authors.lastname: Grandjean
authors.forename: D
authors.initials: D
authors.lastname: Lancelin
authors.forename: T
authors.initials: T
authors.lastname: Lhomme
authors.forename: A
authors.initials: A
authors.lastname: Vivrel
authors.forename: I
authors.initials: I
authors.lastname: Small
mesh_terms: D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000235:genetics*; D000818:Animals; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D001226:Aspartate-tRNA Ligase; D001483:Base Sequence; D017931:DNA Primers; D018076:DNA, Complementary; D020440:Gene Duplication; D006801:Humans; D008969:Molecular Sequence Data; D015388:Organelles / Q000201:enzymology; D010802:Phylogeny; D012346:RNA, Transfer, Amino Acyl; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D012346:RNA, Transfer, Amino Acyl; D000604:Amino Acyl-tRNA Synthetases; D001226:Aspartate-tRNA Ligase; C019975:cysteinyl-tRNA synthetase; C029194:asparaginyl-tRNA synthetase