Publications

• Incorporation of amino acids into ribonucleic acid. I. The role of activating enzymes.

  ALLEN E.H., GLASSMAN E., SCHWEET R.S.

  J Biol Chem 235:1061-1067(1960) [PubMed] [EuropePMC]

  This publication is cited by 4 other entries.

• RNA-assisted catalysis in a protein enzyme: The 2'-hydroxyl of tRNA(Thr) A76 promotes aminoacylation by threonyl-tRNA synthetase.

  Minajigi A., Francklyn C.S.

  Aminoacyl-tRNA synthetases (aaRSs) join amino acids to 1 of 2 terminal hydroxyl groups of their cognate tRNAs, thereby contributing to the overall fidelity of protein synthesis. In class II histidyl-tRNA synthetase (HisRS) the nonbridging S(p)-oxygen of the adenylate is a potential general base fo ... >> More

  Aminoacyl-tRNA synthetases (aaRSs) join amino acids to 1 of 2 terminal hydroxyl groups of their cognate tRNAs, thereby contributing to the overall fidelity of protein synthesis. In class II histidyl-tRNA synthetase (HisRS) the nonbridging S(p)-oxygen of the adenylate is a potential general base for aminoacyl transfer. To test for conservation of this mechanism in other aaRSs and the role of terminal hydroxyls of tRNA in aminoacyl transfer, we investigated the class II Escherichia coli threonyl-tRNA synthetase (ThrRS). As with other class II aaRSs, the rate-determining step for ThrRS is amino acid activation. In ThrRS, however, the 2'-OH of A76 of tRNA(Thr) and a conserved active-site histidine (His-309) collaborate to catalyze aminoacyl transfer by a mechanism distinct from HisRS. Conserved residues in the ThrRS active site were replaced with alanine, and then the resulting mutant proteins were analyzed by steady-state and rapid kinetics. Nearly all mutants preferentially affected the amino acid activation step, with only a modest effect on aminoacyl transfer. By contrast, H309A ThrRS decreased transfer 242-fold and imposed a kinetic block to CCA accommodation. His-309 hydrogen bonds to the 2'-OH of A76, and substitution of the latter by hydrogen or fluorine decreased aminoacyl transfer by 763- and 94-fold, respectively. The proton relay mechanism suggested by these data to promote aminoacylation is reminiscent of the NAD(+)-dependent mechanisms of alcohol dehydrogenases and sirtuins and the RNA-mediated catalysis of the ribosomal peptidyl transferase center. << Less

  Proc. Natl. Acad. Sci. U.S.A. 105:17748-17753(2008) [PubMed] [EuropePMC]

• Zinc ion mediated amino acid discrimination by threonyl-tRNA synthetase.

  Sankaranarayanan R., Dock-Bregeon A.-C., Rees B., Bovee M., Caillet J., Romby P., Francklyn C.S., Moras D.

  Accurate translation of the genetic code depends on the ability of aminoacyl-tRNA synthetases to distinguish between similar amino acids. In order to investigate the basis of amino acid recognition and to understand the role played by the zinc ion present in the active site of threonyl-tRNA synthe ... >> More

  Accurate translation of the genetic code depends on the ability of aminoacyl-tRNA synthetases to distinguish between similar amino acids. In order to investigate the basis of amino acid recognition and to understand the role played by the zinc ion present in the active site of threonyl-tRNA synthetase, we have determined the crystal structures of complexes of an active truncated form of the enzyme with a threonyl adenylate analog or threonine. The zinc ion is directly involved in threonine recognition, forming a pentacoordinate intermediate with both the amino group and the side chain hydroxyl. Amino acid activation experiments reveal that the enzyme shows no activation of isosteric valine, and activates serine at a rate 1,000-fold less than that of cognate threonine. This study demonstrates that the zinc ion is neither strictly catalytic nor structural and suggests how the zinc ion ensures that only amino acids that possess a hydroxyl group attached to the beta-position are activated. << Less

  Nat. Struct. Biol. 7:461-465(2000) [PubMed] [EuropePMC]

• Partial purification of the threonine- and tyrosine-activating enzymes from rat liver, and the effect of patassium ions on the activity of the tyrosine enzyme.

  HOLLEY R.W., BRUNNGRABER E.F., SAAD F., WILLIAMS H.H.

  J Biol Chem 236:197-199(1961) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• The structure of threonyl-tRNA synthetase-tRNA(Thr) complex enlightens its repressor activity and reveals an essential zinc ion in the active site.

  Sankaranarayanan R., Dock-Bregeon A.-C., Romby P., Caillet J., Springer M., Rees B., Ehresmann C., Ehresmann B., Moras D.

  E. coli threonyl-tRNA synthetase (ThrRS) is a class II enzyme that represses the translation of its own mRNA. We report the crystal structure at 2.9 A resolution of the complex between tRNA(Thr) and ThrRS, whose structural features reveal novel strategies for providing specificity in tRNA selectio ... >> More

  E. coli threonyl-tRNA synthetase (ThrRS) is a class II enzyme that represses the translation of its own mRNA. We report the crystal structure at 2.9 A resolution of the complex between tRNA(Thr) and ThrRS, whose structural features reveal novel strategies for providing specificity in tRNA selection. These include an amino-terminal domain containing a novel protein fold that makes minor groove contacts with the tRNA acceptor stem. The enzyme induces a large deformation of the anticodon loop, resulting in an interaction between two adjacent anticodon bases, which accounts for their prominent role in tRNA identity and translational regulation. A zinc ion found in the active site is implicated in amino acid recognition/discrimination. << Less

  Cell 97:371-381(1999) [PubMed] [EuropePMC]

• Aminoacyl-tRNA synthesis.

  Ibba M., Soll D.

  Aminoacyl-tRNAs are substrates for translation and are pivotal in determining how the genetic code is interpreted as amino acids. The function of aminoacyl-tRNA synthesis is to precisely match amino acids with tRNAs containing the corresponding anticodon. This is primarily achieved by the direct a ... >> More

  Aminoacyl-tRNAs are substrates for translation and are pivotal in determining how the genetic code is interpreted as amino acids. The function of aminoacyl-tRNA synthesis is to precisely match amino acids with tRNAs containing the corresponding anticodon. This is primarily achieved by the direct attachment of an amino acid to the corresponding tRNA by an aminoacyl-tRNA synthetase, although intrinsic proofreading and extrinsic editing are also essential in several cases. Recent studies of aminoacyl-tRNA synthesis, mainly prompted by the advent of whole genome sequencing and the availability of a vast body of structural data, have led to an expanded and more detailed picture of how aminoacyl-tRNAs are synthesized. This article reviews current knowledge of the biochemical, structural, and evolutionary facets of aminoacyl-tRNA synthesis. << Less

  Annu Rev Biochem 69:617-650(2000) [PubMed] [EuropePMC]

  This publication is cited by 26 other entries.