title: Human asparaginyl-tRNA synthetase: molecular cloning and the inference of the evolutionary history of Asx-tRNA synthetase family.
abstract: We have cloned and sequenced a cDNA encoding human cytoplasmic asparaginyl-tRNA synthetase (AsnRS). The N-terminal appended domain of 112 amino acid represents the signature sequence for the eukaryotic AsnRS and is absent from archaebacterial or eubacterial enzymes. The canonical ortholog for AsnRS is absent from most archaebacterial and some eubacterial genomes, indicating that in those organisms, formation of asparaginyl-tRNA is independent of the enzyme. The high degree of sequence conservation among asparaginyl- and aspartyl-tRNA synthetases (AsxRS) made it possible to infer the evolutionary paths of the two enzymes. The data show the neighbor relationship between AsnRS and eubacterial aspartyl-tRNA synthetase, and support the occurrence of AsnRS early in the course of evolution, which is in contrast to the proposed late occurrence of glutaminyl-tRNA synthetase.
authors.affiliation: Department of Cell Biology, Cancer Institute, Japanese Foundation for Cancer Research, 1-37-1 Kami-Ikebukuro, Toshima, Tokyo 170-8455, Japan. kshiba@jfcr.or.jp
authors.forename: K
authors.initials: K
authors.lastname: Shiba
authors.forename: H
authors.initials: H
authors.lastname: Motegi
authors.forename: M
authors.initials: M
authors.lastname: Yoshida
authors.forename: T
authors.initials: T
authors.lastname: Noda
mesh_terms: D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics*; D001105:Archaea / Q000201:enzymology / Q000235:genetics; D001226:Aspartate-tRNA Ligase / Q000235:genetics; D001419:Bacteria / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D019143:Evolution, Molecular; D005975:Glutamate-tRNA Ligase / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; 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; D005975:Glutamate-tRNA Ligase; C020659:glutaminyl-tRNA synthetase; C029194:asparaginyl-tRNA synthetase