1b5o

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THERMUS THERMOPHILUS ASPARTATE AMINOTRANSFERASE SINGLE MUTANT 1THERMUS THERMOPHILUS ASPARTATE AMINOTRANSFERASE SINGLE MUTANT 1

Structural highlights

1b5o is a 2 chain structure with sequence from Thermus thermophilus HB8. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.2Å
Ligands:,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

AAPAT_THET8 Catalyzes the reversible conversion of aspartate and 2-oxoglutarate to glutamate and oxaloacetate (PubMed:8907187, PubMed:25070637). Can also transaminate prephenate in the presence of aspartate (PubMed:25070637, PubMed:30771275).[1] [2] [3]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Aspartate aminotransferase from an extremely thermophilic bacterium, Thermus thermophilus HB8 (ttAspAT), has been believed to be specific for an acidic substrate. However, stepwise introduction of mutations in the active-site residues finally changed its substrate specificity to that of a dual-substrate enzyme. The final mutant, [S15D, T17V, K109S, S292R] ttAspAT, is active toward both acidic and hydrophobic substrates. During the course of stepwise mutation, the activities toward acidic and hydrophobic substrates changed independently. The introduction of a mobile Arg292* residue into ttAspAT was the key step in the change to a "dual-substrate" enzyme. The substrate recognition mechanism of this thermostable "dual-substrate" enzyme was confirmed by X-ray crystallography. This work together with previous studies on various enzymes suggest that this unique "dual-substrate recognition" mechanism is a feature of not only aminotransferases but also other enzymes.

Substrate recognition mechanism of thermophilic dual-substrate enzyme.,Ura H, Nakai T, Kawaguchi SI, Miyahara I, Hirotsu K, Kuramitsu S J Biochem. 2001 Jul;130(1):89-98. PMID:11432784[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Dornfeld C, Weisberg AJ, K C R, Dudareva N, Jelesko JG, Maeda HA. Phylobiochemical characterization of class-Ib aspartate/prephenate aminotransferases reveals evolution of the plant arogenate phenylalanine pathway. Plant Cell. 2014 Jul;26(7):3101-14. PMID:25070637 doi:10.1105/tpc.114.127407
  2. Giustini C, Graindorge M, Cobessi D, Crouzy S, Robin A, Curien G, Matringe M. Tyrosine metabolism: identification of a key residue in the acquisition of prephenate aminotransferase activity by 1beta aspartate aminotransferase. FEBS J. 2019 Feb 16. doi: 10.1111/febs.14789. PMID:30771275 doi:http://dx.doi.org/10.1111/febs.14789
  3. Okamoto A, Kato R, Masui R, Yamagishi A, Oshima T, Kuramitsu S. An aspartate aminotransferase from an extremely thermophilic bacterium, Thermus thermophilus HB8. J Biochem. 1996 Jan;119(1):135-44. PMID:8907187 doi:10.1093/oxfordjournals.jbchem.a021198
  4. Ura H, Nakai T, Kawaguchi SI, Miyahara I, Hirotsu K, Kuramitsu S. Substrate recognition mechanism of thermophilic dual-substrate enzyme. J Biochem. 2001 Jul;130(1):89-98. PMID:11432784

1b5o, resolution 2.20Å

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