INA complex liaises the F<sub>1</sub>F<sub>o</sub>-ATP synthase membrane motor modules.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29093463.
- Also identified by DOI 10.1038/s41467-017-01437-z and PMC identifier 5665977.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The F<sub>1</sub>F<sub>0</sub>-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<sup>+</sup>-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<sub>1</sub>-portion is built on Atp6/8 and loss of INAC causes accumulation of the free F<sub>1</sub>. An independent complex is formed between INAC and the Atp9 ring. We conclude that INAC maintains assembly intermediates of the F<sub>1</sub> F<sub>0</sub>-ATP synthase in a primed state for the terminal assembly step-motor module formation.
Medical subject headings
- Mitochondrial Membranes
- Mitochondrial Proton-Translocating ATPases
- Protons
- Saccharomyces cerevisiae Proteins