2ODX

Solution structure of Zn(II)Cox4

Summary for 2ODX

• Entry DOI: 10.2210/pdb2odx/pdb
• Descriptor: Cytochrome c oxidase polypeptide IV, ZINC ION (2 entities in total)
• Functional Keywords: all beta-protein, metallo-protein, oxidoreductase
• Biological source: Saccharomyces cerevisiae (baker's yeast)
• Cellular location: Mitochondrion inner membrane: P04037
• Total number of polymer chains: 1
• Total formula weight: 9062.58

Authors

Coyne III, J.H.,Ciofi-Baffoni, S. (deposition date: 2006-12-27, release date: 2007-01-09, Last modification date: 2023-12-27)

Primary citation

Coyne, H.J.,Ciofi-Baffoni, S.,Banci, L.,Bertini, I.,Zhang, L.,George, G.N.,Winge, D.R.
The characterization and role of zinc binding in yeast cox4.
J.Biol.Chem., 282:8926-8934, 2007

PubMed Abstract: Yeast Cox4 is a zinc binding subunit of cytochrome c oxidase. Cox4 is the only cofactor-containing subunit that is not directly part of the catalytic core of the enzyme located in the mitochondrial inner membrane. The Zn(II) site is shown to be distinct from the bovine ortholog, as it results from the x-ray structure of the entire cytochrome c oxidase in having a single histidyl residue and three conserved cysteines residues in the coordination sphere. Substitutions at the Cys ligand positions result in non-functional Cox4 proteins that fail to lead to cytochrome oxidase assembly. Limited function exists in His-119 mutants when overexpressed. Zn(II) binding in Cox4 is, therefore, important for the stability of the complex. The solution structure of yeast Cox4 elucidated by multidimensional NMR reveals a C-terminal globular domain consisting of two beta sheets analogous to the bovine ortholog except the loop containing the coordinating His in the yeast protein and the fourth Cys in the bovine protein are in different positions in the two structures. The conformation of this loop is dictated by the different sequence position of the fourth coordinating zinc ligand. The Zn(II) ion is buried within the domain, consistent with its role in structural stability. Potential functions of this matrix-facing subunit are discussed.

PubMed: 17215247
DOI: 10.1074/jbc.M610303200

Experimental method

SOLUTION NMR