Evidence of a subunit 4 (subunit b) dimer in favor of the proximity of ATP synthase complexes in yeast inner mitochondrial membrane.
Yeast mitochondria having either the D54C or E55C mutations in subunit 4 (subunit b), which is a component of the ATP synthase stator, displayed a spontaneous disulfide bridge between two subunits 4. This dimer was not soluble upon Triton X-100 extraction either at concentrations which extract the yeast ATP synthase or at higher concentrations. Increasing detergent concentrations led to a lack of the oligomycin-sensitive ATPase activity, thus showing an uncoupling between the two sectors of the mutated enzymes due to the dissociation of the subunit 4 dimer from the mutant enzyme. There is only one subunit 4 (subunit b) per eukaryotic ATP synthase. As a consequence, the results are interpreted as the proximity of ATP synthase complexes within the inner mitochondrial membrane.
Spannagel
C
C
Institut de Biochimie et Génétique Cellulaires du CNRS, Université Victor Ségalen, Bordeaux II, 1 rue Camille Saint Saëns, 33077 Bordeaux Cedex, France.
Vaillier
J
J
Arselin
G
G
Graves
P V
PV
Grandier-Vazeille
X
X
Velours
J
J
D007425:Intracellular Membranes / Q000201:enzymology; D008928:Mitochondria / Q000201:enzymology; D009154:Mutation; D009840:Oligomycins; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure
D009840:Oligomycins; D006180:Proton-Translocating ATPases