INA complex liaises the F 1 F o -ATP synthase membrane motor modules

• Published in: Nature communications Vol. 8; no. 1; p. 1237
• Main Authors: Naumenko, Nataliia, Morgenstern, Marcel, Rucktäschel, Robert, Warscheid, Bettina, Rehling, Peter
• Format: Journal Article
• Language: English
• Published: England 01.11.2017
• Subjects: Adenosine Diphosphate - metabolism; Adenosine Triphosphate - metabolism; Gene Expression Regulation, Fungal; Mitochondrial Membranes - metabolism; Mitochondrial Proton-Translocating ATPases - genetics; Mitochondrial Proton-Translocating ATPases - metabolism; Protons; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism
• ISSN: 2041-1723

The F F -ATP synthase translates a proton flux across the inner mitochondrial membrane into a mechanical rotation, driving anhydride bond formation in the catalytic portion. The complex's membrane-embedded motor forms a proteinaceous channel at the interface between Atp9 ring and Atp6. To prevent unrestricted proton flow dissipating the H -gradient, channel formation is a critical and tightly controlled step during ATP synthase assembly. Here we show that the INA complex (INAC) acts at this decisive step promoting Atp9-ring association with Atp6. INAC binds to newly synthesized mitochondrial-encoded Atp6 and Atp8 in complex with maturation factors. INAC association is retained until the F -portion is built on Atp6/8 and loss of INAC causes accumulation of the free F . An independent complex is formed between INAC and the Atp9 ring. We conclude that INAC maintains assembly intermediates of the F F -ATP synthase in a primed state for the terminal assembly step-motor module formation.