Cox17 is a key mitochondrial copper chaperone involved in the assembly of cytochrome c oxidase (COX). The NMR solution structure of the oxidized apoCox17 isoform consists of a coiled-coil conformation stabilized by two disulfide bonds involving Cys26/Cys57 and Cys36/Cys 47. This appears to be a conserved tertiary fold of a class of proteins, localized within the mitochondrial intermembrane space, that contain a twin Cys-x9-Cys sequence motif. An isomerization of one disulfide bond from Cys26/Cys57 to Cys24/Cys57 is required prior to Cu(I) binding to form the Cu1Cox17 complex. Upon further oxidation of the apo-protein, a form with three disulfide bonds is obtained. The reduction of all disulfide bonds provides a molten globule form that can convert to an additional conformer capable of binding up to four Cu(I) ions in a polycopper cluster. This form of the protein is oligomeric. These properties are framed within a complete model of mitochondrial import and COX assembly. ©2005 Elsevier Ltd All rights reserved.
Folding studies of Cox17 reveal an important interplay of cysteine oxidation and copper binding / F.Arnesano; E.Balatri; L.Banci; I.Bertini; D.R.Winge. - In: STRUCTURE. - ISSN 0969-2126. - STAMPA. - 13:(2005), pp. 713-722. [10.1016/j.str.2005.02.015]
Folding studies of Cox17 reveal an important interplay of cysteine oxidation and copper binding
BANCI, LUCIA;BERTINI, IVANO;
2005
Abstract
Cox17 is a key mitochondrial copper chaperone involved in the assembly of cytochrome c oxidase (COX). The NMR solution structure of the oxidized apoCox17 isoform consists of a coiled-coil conformation stabilized by two disulfide bonds involving Cys26/Cys57 and Cys36/Cys 47. This appears to be a conserved tertiary fold of a class of proteins, localized within the mitochondrial intermembrane space, that contain a twin Cys-x9-Cys sequence motif. An isomerization of one disulfide bond from Cys26/Cys57 to Cys24/Cys57 is required prior to Cu(I) binding to form the Cu1Cox17 complex. Upon further oxidation of the apo-protein, a form with three disulfide bonds is obtained. The reduction of all disulfide bonds provides a molten globule form that can convert to an additional conformer capable of binding up to four Cu(I) ions in a polycopper cluster. This form of the protein is oligomeric. These properties are framed within a complete model of mitochondrial import and COX assembly. ©2005 Elsevier Ltd All rights reserved.
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