Dimerization of bovine F1-ATPase by binding the inhibitor protein, IF1.

TitleDimerization of bovine F1-ATPase by binding the inhibitor protein, IF1.
Publication TypeJournal Article
Year of Publication2000
AuthorsCabezón, E, Arechaga, I, Jonathan, P, Butler, G, Walker, JE
JournalJ Biol Chem
Volume275
Issue37
Pagination28353-5
Date Published2000 Sep 15
ISSN0021-9258
KeywordsAnimals, Cattle, Dimerization, Enzyme Inhibitors, Microscopy, Electron, Molecular Weight, Protein Conformation, Proton-Translocating ATPases
Abstract

In mitochondria, the hydrolytic activity of ATP synthase is regulated by a natural inhibitor protein, IF(1). The binding of IF(1) to ATP synthase depends on pH values, and below neutrality, IF(1) forms a stable complex with the enzyme. Bovine IF(1) has two oligomeric states, dimer and tetramer, depending on pH values. At pH 6.5, where it is active, IF(1) dimerizes by formation of an antiparallel alpha-helical coiled-coil in its C-terminal region. This arrangement places the inhibitory N-terminal regions in opposition, implying that active dimeric IF(1) can bind two F(1) domains simultaneously. Evidence of dimerization of F(1)-ATPase by binding to IF(1) is provided by gel filtration chromatography, analytical ultracentrifugation, and electron microscopy. At present, it is not known whether IF(1) can bring about the dimerization of the F(1)F(0)-ATPase complex.

DOI10.1074/jbc.C000427200
Alternate JournalJ. Biol. Chem.
Citation Key10.1074/jbc.C000427200
PubMed ID10918052