title: Functional convergence of two lysyl-tRNA synthetases with unrelated topologies.
abstract: Lysyl-tRNA can be synthesized by both a class I (LysRS-I) and a class II (LysRS-II) lysyl-tRNA synthetase. The crystal structure of LysRS-I from Pyrococcus horikoshii at 2.6 A resolution reveals extensive similarity with glutamyl-tRNA synthetase (GluRS). A comparison of the structures of LysRS-I and LysRS-II in complex with lysine shows that both enzymes use similar strategies for substrate recognition within unrelated active site topologies. A docking model based upon the GluRS-tRNA complex suggests how LysRS-I and LysRS-II can recognize the same molecular determinants in tRNALys, as shown by biochemical results, while approaching the acceptor helix of the tRNA from opposite sides.
authors.affiliation: RIKEN Genomic Sciences Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.
authors.forename: Takaho
authors.initials: T
authors.lastname: Terada
authors.forename: Osamu
authors.initials: O
authors.lastname: Nureki
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Ishitani
authors.forename: Alexandre
authors.initials: A
authors.lastname: Ambrogelly
authors.forename: Michael
authors.initials: M
authors.lastname: Ibba
authors.forename: Dieter
authors.initials: D
authors.lastname: Söll
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
mesh_terms: D000215:Acylation; D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D019143:Evolution, Molecular; D005975:Glutamate-tRNA Ligase / Q000737:chemistry; D008239:Lysine / Q000378:metabolism*; D008250:Lysine-tRNA Ligase / Q000737:chemistry* / Q000145:classification / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D019711:Pyrococcus / Q000201:enzymology*; D016415:Sequence Alignment; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D005975:Glutamate-tRNA Ligase; D008250:Lysine-tRNA Ligase; D008239:Lysine