Overview for MACiE Entry M0197
EC Number: 18.104.22.168 (A member of the Ligases, Forming carbon-oxygen bonds, Ligases forming aminoacyl-tRNA and related compounds)
Enzyme Name: tyrosine-tRNA ligase
Biological Species: Bacillus stearothermophilus (Bacteria)
Catalytic Chain UniprotKB Accession Codes:
- P00952 - Tyrosyl-tRNA synthetase
Representative PDB Code: 2ts1 - STRUCTURE OF TYROSYL-T/RNA SYNTHETASE REFINED AT 2.3 ANGSTROMSRESOLUTION. INTERACTION OF THE ENZYME WITH THE TYROSYL ADENYLATEINTERMEDIATE (Resolution = 2.30 Å).
Catalytic CATH Codes:
- 22.214.171.1240 - Tyrosyl-Transfer RNA Synthetase , subunit E, domain 1
- 126.96.36.199 - Tyrosyl-Transfer RNA Synthetase
Display structure information
Overall Comment: The position of the Mg(II) within the active site of tyrosyl-tRNA synthetase is not apparent from the X-ray crystal structure. It also appears that substrate binding induces a conformational change that brings the residues Lys82 and Arg86 into range .
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Stepwise Description of the Reaction
|Step 1||The carboxylate group of the substrate L-tyrosine acts as a nucleophile and attacks the alpha-phosphate of the ATP in a substitution reaction that liberates pyrophosphate. Mg(II) and all catalytic residues stabilise the intermediates formed. Thr234 also affects the steric outcome of the reaction.|
|Step 2||The phosphate of the tyrosine-AMP complex deprotonates the OH of the ribose ring, which acts as a nucleophile to attack the carbonyl group of the tyrosine in the tyrosine-AMP complex in a substitution reaction, liberating AMP. Mg(II), Thr40, His48, Lys82, Arg86 and Gln173 all stabilise the intermediates formed.|
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Catalytic Residues Involved
||Location of Function
Metal Cofactors for M0197
||MG(not in PDB)
- A. R. Fersht et al. (1988), Biochemistry, 27, 1581-1587. Reconstruction by site-directed mutagenesis of the transition state for the activation of tyrosine by the tyrosyl-tRNA synthetase: a mobile loop envelopes the transition state in an induced-fit mechanism.
- Y. Xin et al. (2000), J. Mol. Biol., 303, 299-310. Stabilization of the transition state for the transfer of tyrosine to tRNA(Tyr) by tyrosyl-tRNA synthetase.
- Y. Xin et al. (2000), J. Mol. Biol., 303, 287-298. Correlating amino acid conservation with function in tyrosyl-tRNA synthetase.
- E. A. First et al. (1993), Biochemistry, 32, 13644-13650. Involvement of threonine 234 in catalysis of tyrosyl adenylate formation by tyrosyl-tRNA synthetase.
- M. G. Caprara et al. (2001), J. Mol. Biol., 308, 165-190. Interaction of the Neurospora crassa mitochondrial tyrosyl-tRNA synthetase (CYT-18 protein) with the group I intron P4-P6 domain. Thermodynamic analysis and the role of metal ions.
Homologue information for M0197 (2ts1)
MACiE Homologues (within the PDB)
MACiE Homologues (within UniprotKB/SwissProt)
Entries with at least one Catalytic CATH code in common (different mechanisms):
|M0279 ||phosphoadenylyl-sulfate reductase (thioredoxin) |
|M0299 ||pantetheine-phosphate adenylyltransferase |
|M0287 ||sulfate adenylyltransferase |
|M0296 ||glycerol-3-phosphate cytidylyltransferase |
|M0309 ||isoleucine-tRNA ligase |
|M0235 ||arginine-tRNA ligase |
|M0229 ||pantoate-beta-alanine ligase |
|M0303 ||(carboxyethyl)arginine beta-lactam-synthase |
|M0316 ||argininosuccinate synthetase |
|M0234 ||GMP synthase (glutamine-hydrolysing) |
|M0302 ||asparagine synthase (glutamine-hydrolysing) |
View a comparison of the other reactions in MACiE with the CATH domain 188.8.131.520
Links to this entry in other databases