Two ATP synthases can be linked through subunits i in the inner mitochondrial membrane of Saccharomyces cerevisiae.

Patrick Paumard, Geneviève Arselin, Jacques Vaillier, Stéphane Chaignepain, Katell Bathany, Jean Marie Schmitter, Daniel Brèthes, Jean Velours

Index: Biochemistry 41(33) , 10390-6, (2002)

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Abstract

Cross-linking experiments showed that the supernumerary subunit i is close to the interface between two ATP synthases. These data were used to demonstrate the presence of ATP synthase dimers in the inner mitochondrial membrane of Saccharomyces cerevisiae. A cysteine residue was introduced into the inter-membrane space located C-terminal part of subunit i. Cross-linking experiments revealed a dimerization of subunit i. This cross-linking occurred only with the dimeric form of the enzyme after incubating intact mitochondria with a bis-maleimide reagent, thus indicating an inter-ATP synthase cross-linking, whereas the monomeric form of the enzyme exhibited only an intra-ATP synthase cross-linking with subunit 6, another component of the membranous domain of the ATP synthase.