title: A euryarchaeal lysyl-tRNA synthetase: resemblance to class I synthetases.
abstract: The sequencing of euryarchaeal genomes has suggested that the essential protein lysyl-transfer RNA (tRNA) synthetase (LysRS) is absent from such organisms. However, a single 62-kilodalton protein with canonical LysRS activity was purified from Methanococcus maripaludis, and the gene that encodes this protein was cloned. The predicted amino acid sequence of M. maripaludis LysRS is similar to open reading frames of unassigned function in both Methanobacterium thermoautotrophicum and Methanococcus jannaschii but is unrelated to canonical LysRS proteins reported in eubacteria, eukaryotes, and the crenarchaeote Sulfolobus solfataricus. The presence of amino acid motifs characteristic of the Rossmann dinucleotide-binding domain identifies M. maripaludis LysRS as a class I aminoacyl-tRNA synthetase, in contrast to the known examples of this enzyme, which are class II synthetases. These data question the concept that the classification of aminoacyl-tRNA synthetases does not vary throughout living systems.
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Yale University, Post Office Box 208114, 266 Whitney Avenue, New Haven, CT 06520-8114, USA.
authors.forename: M
authors.initials: M
authors.lastname: Ibba
authors.forename: S
authors.initials: S
authors.lastname: Morgan
authors.forename: A W
authors.initials: AW
authors.lastname: Curnow
authors.forename: D R
authors.initials: DR
authors.lastname: Pridmore
authors.forename: U C
authors.initials: UC
authors.lastname: Vothknecht
authors.forename: W
authors.initials: W
authors.lastname: Gardner
authors.forename: W
authors.initials: W
authors.lastname: Lin
authors.forename: C R
authors.initials: CR
authors.lastname: Woese
authors.forename: D
authors.initials: D
authors.lastname: Söll
mesh_terms: D000215:Acylation; D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000201:enzymology; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D019605:Euryarchaeota / Q000201:enzymology / Q000235:genetics; D019143:Evolution, Molecular; D019766:Genes, Archaeal; D006801:Humans; D007700:Kinetics; D008250:Lysine-tRNA Ligase / Q000737:chemistry* / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D017017:Methanococcus / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012346:RNA, Transfer, Amino Acyl / Q000096:biosynthesis; D016415:Sequence Alignment; D016944:Sulfolobus / Q000201:enzymology
chemical_list: D012346:RNA, Transfer, Amino Acyl; D008250:Lysine-tRNA Ligase