Functional convergence of two lysyl-tRNA synthetases with unrelated topologies

Nat Struct Biol. 2002 Apr;9(4):257-62. doi: 10.1038/nsb777.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acylation
  • Amino Acid Sequence
  • Binding Sites
  • Crystallography, X-Ray
  • Evolution, Molecular*
  • Glutamate-tRNA Ligase / chemistry
  • Lysine / metabolism*
  • Lysine-tRNA Ligase / chemistry*
  • Lysine-tRNA Ligase / classification
  • Lysine-tRNA Ligase / metabolism*
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Pyrococcus / enzymology*
  • Sequence Alignment
  • Structure-Activity Relationship
  • Substrate Specificity

Substances

  • Glutamate-tRNA Ligase
  • Lysine-tRNA Ligase
  • Lysine

Associated data

  • PDB/1IRX