2P3X

Crystal structure of Grenache (Vitis vinifera) Polyphenol Oxidase

Summary for 2P3X

• Entry DOI: 10.2210/pdb2p3x/pdb
• Descriptor: Polyphenol oxidase, chloroplast, CU-O-CU LINKAGE (3 entities in total)
• Functional Keywords: polyphenol oxidase, grenache grapes, oxidoreductase
• Biological source: Vitis vinifera
• Cellular location: Plastid, chloroplast thylakoid lumen: P43311
• Total number of polymer chains: 1
• Total formula weight: 38611.45

Authors

Reyes Grajeda, J.P.,Virador, V.M.,Blanco-Labra, A.,Mendiola-Olaya, E.,Smith, G.M.,Moreno, A.,Whitaker, J.R. (deposition date: 2007-03-09, release date: 2008-03-11, Last modification date: 2024-10-30)

Primary citation

Virador, V.M.,Reyes Grajeda, J.P.,Blanco-Labra, A.,Mendiola-Olaya, E.,Smith, G.M.,Moreno, A.,Whitaker, J.R.
Cloning, sequencing, purification, and crystal structure of Grenache (Vitis vinifera) polyphenol oxidase.
J.Agric.Food Chem., 58:1189-1201, 2010

PubMed Abstract: The full-length cDNA sequence (P93622_VITVI) of polyphenol oxidase (PPO) cDNA from grape Vitis vinifera L., cv Grenache, was found to encode a translated protein of 607 amino acids with an expected molecular weight of ca. 67 kDa and a predicted pI of 6.83. The translated amino acid sequence was 99%, identical to that of a white grape berry PPO (1) (5 out of 607 amino acid potential sequence differences). The protein was purified from Grenache grape berries by using traditional methods, and it was crystallized with ammonium acetate by the hanging-drop vapor diffusion method. The crystals were orthorhombic, space group C222(1). The structure was obtained at 2.2 A resolution using synchrotron radiation using the 39 kDa isozyme of sweet potato PPO (PDB code: 1BT1 ) as a phase donor. The basic symmetry of the cell parameters (a, b, and c and alpha, beta, and gamma) as well as in the number of asymmetric units in the unit cell of the crystals of PPO, differed between the two proteins. The structures of the two enzymes are quite similar in overall fold, the location of the helix bundles at the core, and the active site in which three histidines bind each of the two catalytic copper ions, and one of the histidines is engaged in a thioether linkage with a cysteine residue. The possibility that the formation of the Cys-His thioether linkage constitutes the activation step is proposed. No evidence of phosphorylation or glycoslyation was found in the electron density map. The mass of the crystallized protein appears to be only 38.4 kDa, and the processing that occurs in the grape berry that leads to this smaller size is discussed.

PubMed: 20039636
DOI: 10.1021/jf902939q

Experimental method

X-RAY DIFFRACTION (2.2 Å)