An Unconventional Copper Protein Required for Cytochrome c Oxidase Respiratory Function under Extreme Acidic Conditions |
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Authors: | Cindy Castelle Marianne Ilbert Pascale Infossi Gisèle Leroy Marie-Thérèse Giudici-Orticoni |
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Institution: | From the Laboratoire de Bioénergétique et Ingénierie des Protéines, IMM-CNRS, 13402 Marseille Cedex 20, France |
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Abstract: | Very little is known about the processes used by acidophile organisms to preserve stability and function of respiratory pathways. Here, we reveal a potential strategy of these organisms for protecting and keeping functional key enzymes under extreme conditions. Using Acidithiobacillus ferrooxidans, we have identified a protein belonging to a new cupredoxin subfamily, AcoP, for “acidophile CcO partner,” which is required for the cytochrome c oxidase (CcO) function. We show that it is a multifunctional copper protein with at least two roles as follows: (i) as a chaperone-like protein involved in the protection of the CuA center of the CcO complex and (ii) as a linker between the periplasmic cytochrome c and the inner membrane cytochrome c oxidase. It could represent an interesting model for investigating the multifunctionality of proteins known to be crucial in pathways of energy metabolism. |
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Keywords: | Bioenergetics Copper Cytochrome Oxidase Membrane Enzymes Metalloproteins Acidophile Chaperone-like Cupredoxin |
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