Refined crystal structure of the seryl-tRNA synthetase from Thermus thermophilus at 2.5 A resolution

J Mol Biol. 1993 Nov 5;234(1):222-33. doi: 10.1006/jmbi.1993.1576.


The three-dimensional structure of the seryl-tRNA synthetase from Thermus thermophilus has been determined and refined at 2.5 A resolution. The final model consists of a dimer of 421 residues each and 190 water molecules. The R-factor is 18.4% for all the data between 10 and 2.5 A resolution. The structure is very similar to that of the homologous enzyme from Escherichia coli, with an r.m.s. difference of 1.5 A for the 357 alpha-carbon atoms considered equivalent. The comparison of the two structures indicates increased hydrophobicity, reduced conformational entropy and reduced torsional strain as possible mechanisms by which thermostability is obtained in the enzyme from the thermophile.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / ultrastructure
  • Crystallography, X-Ray
  • Escherichia coli / enzymology
  • Fungal Proteins / ultrastructure
  • Hot Temperature
  • Hydrogen Bonding
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Denaturation
  • Protein Structure, Tertiary
  • Saccharomyces cerevisiae / enzymology
  • Sequence Alignment
  • Sequence Homology
  • Serine-tRNA Ligase / ultrastructure*
  • Surface Properties
  • Thermus thermophilus / enzymology*


  • Bacterial Proteins
  • Fungal Proteins
  • Serine-tRNA Ligase