CRYSTALLOGRAPHIC STRUCTURE OF HUMAN BRANCHED CHAIN AMINO ACID AMINOTRANSFERASE (MITOCHONDRIAL) COMPLEXED WITH PYRIDOXAL-5'-PHOSPHATE AT 1.95 ANGSTROMS (ORTHORHOMBIC FORM)CRYSTALLOGRAPHIC STRUCTURE OF HUMAN BRANCHED CHAIN AMINO ACID AMINOTRANSFERASE (MITOCHONDRIAL) COMPLEXED WITH PYRIDOXAL-5'-PHOSPHATE AT 1.95 ANGSTROMS (ORTHORHOMBIC FORM)

Structural highlights

1ekf is a 2 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Activity:Branched-chain-amino-acid transaminase, with EC number 2.6.1.42
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum

Function

[BCAT2_HUMAN] Catalyzes the first reaction in the catabolism of the essential branched chain amino acids leucine, isoleucine, and valine. May also function as a transporter of branched chain alpha-keto acids.

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

X-ray crystal structures of three forms of human mitochondrial branched-chain aminotransferase (BCAT) were solved by molecular-replacement methods, using Escherichia coli BCAT as the search model. The enzyme is a homodimer and the polypeptide chain of each monomer has two domains. The small domain is composed of residues 1--175 and the large domain is composed of residues 176--365. The active site is close to the dimer interface. The 4'-aldehyde of the PLP cofactor is covalently linked to the epsilon-amino group of the active-site lysine, Lys202, via a Schiff-base linkage in two of the structures. In the third structure, the enzyme is irreversibly inactivated by Tris. The overall fold of the dimer in human mitochondrial BCAT is similar to the structure of two bacterial enzymes, E. coli BCAT and D-amino acid aminotransferase (D-AAT). The residues lining the putative substrate-binding pocket of human BCAT and D-AAT are completely rearranged to allow catalysis with substrates of opposite stereochemistry. In the case of human mitochondrial branched-chain aminotransferase, a hydrogen-bond interaction between the guanidinium group of Arg143 in the first monomer with the side-chain hydroxyl of Tyr70 in the second monomer is important in the formation of the substrate-binding pocket.

The structure of human mitochondrial branched-chain aminotransferase.,Yennawar N, Dunbar J, Conway M, Hutson S, Farber G Acta Crystallogr D Biol Crystallogr. 2001 Apr;57(Pt 4):506-15. PMID:11264579[1]

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

See Also

References

  1. Yennawar N, Dunbar J, Conway M, Hutson S, Farber G. The structure of human mitochondrial branched-chain aminotransferase. Acta Crystallogr D Biol Crystallogr. 2001 Apr;57(Pt 4):506-15. PMID:11264579

1ekf, resolution 1.95Å

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