Oligomycin Sensitivity Conferring Protein (OSCP) of Bovine Heart Mitochondrial ATP Synthase:  High-Affinity OSCP−FoInteractions Require a Local α-Helix at the C-Terminal End of the Subunit†

Biochemistry ◽  
1997 ◽  
Vol 36 (36) ◽  
pp. 10936-10943 ◽  
Author(s):  
Saroj Joshi ◽  
Gong Jie Cao ◽  
Cheryl Nath ◽  
Jyotsna Shah
Keyword(s):  
Atp Synthase ◽  
High Affinity ◽  
Bovine Heart ◽  
Mitochondrial Atp Synthase ◽  
Α Helix ◽  
Oligomycin Sensitivity Conferring Protein

scholarly journals Extrinsic conditions influence the self-association and structure of IF1, the regulatory protein of mitochondrial ATP synthase

2019 ◽  
Vol 116 (21) ◽  
pp. 10354-10359 ◽  
Author(s):  
Vytaute Boreikaite ◽  
Basile I. M. Wicky ◽  
Ian N. Watt ◽  
Jane Clarke ◽  
John E. Walker
Keyword(s):  
Atp Synthase ◽  
Atp Hydrolysis ◽  
Regulatory Protein ◽  
Coiled Coil ◽  
The Self ◽  
Intrinsically Disordered ◽  
Mitochondrial Atp Synthase ◽  
Self Association ◽  
Α Helix

The endogenous inhibitor of ATP synthase in mitochondria, called IF1, conserves cellular energy when the proton-motive force collapses by inhibiting ATP hydrolysis. Around neutrality, the 84-amino-acid bovine IF1 is thought to self-assemble into active dimers and, under alkaline conditions, into inactive tetramers and higher oligomers. Dimerization is mediated by formation of an antiparallel α-helical coiled-coil involving residues 44–84. The inhibitory region of each monomer from residues 1–46 is largely α-helical in crystals, but disordered in solution. The formation of the inhibited enzyme complex requires the hydrolysis of two ATP molecules, and in the complex the disordered region from residues 8–13 is extended and is followed by an α-helix from residues 14–18 and a longer α-helix from residue 21, which continues unbroken into the coiled-coil region. From residues 21–46, the long α-helix binds to other α-helices in the C-terminal region of predominantly one of the β-subunits in the most closed of the three catalytic interfaces. The definition of the factors that influence the self-association of IF1 is a key to understanding the regulation of its inhibitory properties. Therefore, we investigated the influence of pH and salt-types on the self-association of bovine IF1 and the folding of its unfolded region. We identified the equilibrium between dimers and tetramers as a potential central factor in the in vivo modulation of the inhibitory activity and suggest that the intrinsically disordered region makes its inhibitory potency exquisitely sensitive and responsive to physiological changes that influence the capability of mitochondria to make ATP.

scholarly journals The Oligomycin-Sensitivity Conferring Protein of Mitochondrial ATP Synthase: Emerging New Roles in Mitochondrial Pathophysiology

2014 ◽  
Vol 15 (5) ◽  
pp. 7513-7536 ◽  
Author(s):  
Manuela Antoniel ◽  
Valentina Giorgio ◽  
Federico Fogolari ◽  
Gary Glick ◽  
Paolo Bernardi ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Mitochondrial Atp Synthase ◽  
Oligomycin Sensitivity Conferring Protein
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