2z9v

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Crystal structure of pyridoxamine-pyruvate aminotransferase complexed with pyridoxamineCrystal structure of pyridoxamine-pyruvate aminotransferase complexed with pyridoxamine

Structural highlights

2z9v is a 2 chain structure with sequence from Mesorhizobium loti. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.7Å
Ligands:, ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

PPAT_RHILO Catalyzes a reversible transamination reaction between pyridoxamine and pyruvate to form pyridoxal and L-alanine.[1] [2]

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

Pyridoxamine-pyruvate aminotransferase (PPAT; EC 2.6.1.30) is a pyridoxal 5'-phosphate-independent aminotransferase and catalyzes reversible transamination between pyridoxamine and pyruvate to form pyridoxal and L-alanine. The crystal structure of PPAT from Mesorhizobium loti has been solved in space group P4(3)2(1)2 and was refined to an R factor of 15.6% (R(free) = 20.6%) at 2.0 A resolution. In addition, the structures of PPAT in complexes with pyridoxamine, pyridoxal, and pyridoxyl-L-alanine have been refined to R factors of 15.6, 15.4, and 14.5% (R(free) = 18.6, 18.1, and 18.4%) at 1.7, 1.7, and 2.0 A resolution, respectively. PPAT is a homotetramer and each subunit is composed of a large N-terminal domain, consisting of seven beta-sheets and eight alpha-helices, and a smaller C-terminal domain, consisting of three beta-sheets and four alpha-helices. The substrate pyridoxal is bound through an aldimine linkage to Lys-197 in the active site. The alpha-carboxylate group of the substrate amino/keto acid is hydrogen-bonded to Arg-336 and Arg-345. The structures revealed that the bulky side chain of Glu-68 interfered with the binding of the phosphate moiety of pyridoxal 5'-phosphate and made PPAT specific to pyridoxal. The reaction mechanism of the enzyme is discussed based on the structures and kinetics results.

Crystal structure of pyridoxamine-pyruvate aminotransferase from Mesorhizobium loti MAFF303099.,Yoshikane Y, Yokochi N, Yamasaki M, Mizutani K, Ohnishi K, Mikami B, Hayashi H, Yagi T J Biol Chem. 2008 Jan 11;283(2):1120-7. Epub 2007 Nov 6. PMID:17989071[3]

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

See Also

References

  1. Yoshikane Y, Yokochi N, Ohnishi K, Hayashi H, Yagi T. Molecular cloning, expression and characterization of pyridoxamine-pyruvate aminotransferase. Biochem J. 2006 Jun 15;396(3):499-507. PMID:16545075 doi:10.1042/BJ20060078
  2. Yoshikane Y, Yokochi N, Yamasaki M, Mizutani K, Ohnishi K, Mikami B, Hayashi H, Yagi T. Crystal structure of pyridoxamine-pyruvate aminotransferase from Mesorhizobium loti MAFF303099. J Biol Chem. 2008 Jan 11;283(2):1120-7. Epub 2007 Nov 6. PMID:17989071 doi:http://dx.doi.org/10.1074/jbc.M708061200
  3. Yoshikane Y, Yokochi N, Yamasaki M, Mizutani K, Ohnishi K, Mikami B, Hayashi H, Yagi T. Crystal structure of pyridoxamine-pyruvate aminotransferase from Mesorhizobium loti MAFF303099. J Biol Chem. 2008 Jan 11;283(2):1120-7. Epub 2007 Nov 6. PMID:17989071 doi:http://dx.doi.org/10.1074/jbc.M708061200

2z9v, resolution 1.70Å

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