Topography of the yeast ATP synthase F0 sector.
The interaction between the hydrophilic C-terminal part of subunit 4 (subunit b) and OSCP, which are two components of the connecting stalk of the yeast ATP synthase, was shown after reconstitution of the two over-expressed proteins and by the two-hybrid method. The organization of a part of the F0 sector was studied by the use of mutants containing cysteine residues in a loop connecting the two N-terminal postulated membrane-spanning segments. Labelling of the mutated subunits 4 by a maleimide fluorescent probe revealed that the sulfhydryl groups were modified upon incubation of intact mitochondria. In addition, non-permeant maleimide reagents labeled subunit 4D54C, thus showing a location of this residue in the intermembrane space. Cross-linking experiments revealed the proximity of subunits 4 and f. In addition, a disulfide bridge between subunit 4D54C and subunit 6 was evidenced, thus demonstrating near-neighbor relationships of the two subunits and a location of the N-terminal part of the mitochondrially-encoded subunit 6 in the intermembrane space.
Velours
J
J
Institut de Biochimie et Génétique Cellulaires du CNRS, Université de Bordeaux II, France.
Spannagel
C
C
Chaignepain
S
S
Vaillier
J
J
Arselin
G
G
Graves
P V
PV
Velours
G
G
Camougrand
N
N
D000251:Adenosine Triphosphatases / Q000378:metabolism; D015153:Blotting, Western; D002352:Carrier Proteins; D008565:Membrane Proteins / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D025261:Mitochondrial Proton-Translocating ATPases; D008954:Models, Biological; D009154:Mutation; D011233:Precipitin Tests; D006180:Proton-Translocating ATPases / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000502:physiology*
D002352:Carrier Proteins; D008565:Membrane Proteins; D000251:Adenosine Triphosphatases; D025261:Mitochondrial Proton-Translocating ATPases; D006180:Proton-Translocating ATPases; C020439:oligomycin sensitivity-conferring protein