Membrane Topology of Subunit 8 Variant of Yeast Saccharomyces cerevisiae Mitochondrial ATP Synthase
DOI:
https://doi.org/10.5454/mi.3.1.7Keywords:
membrane topology, ATP synthase, mitochondria, yeastAbstract
The yeast mitochondrial F1F0-ATP synthase is a multisubunit complex that contains at least 17 different subunits. Subunit 8 of yeast mitochondrial ATP synthase is a hydrophobic protein of 48 amino acids encoded by the mitochondrial ATP8 gene. There is no homologue of subunit 8 found in bacteria. Subunit 8 has three distinct domains; an N-terminal domain, a central hydrophobic domain and a C-terminal domain. Subunit 8 has been shown to adopt a transmembrane topology with the central hydrophobic domain spans the inner mitochondrial membrane once. In order to elucidate the need of subunit 8 to maintain transmembrane topology for its functioning, a severely functionally defective subunit 8 variant that has been introduced with double-charged residues within the central hydrophobic domain was analysed. A gene encoding this variant was expressed in a yeast strain lacking endogenous subunit 8. The subunit 8 variant was then targeted into mitochondria. Following its assembly into mitochondrial ATP synthase complex, its membrane topology was determined. The results obtained showed that subunit 8 was obligatory to maintain a transmembrane topology for providing proper functioning. The transmembrane topology may be critical for subunit 8’s proposed tructural roles as part of the stator stalk of the mitochondrial ATP synthase complex.Downloads
How to Cite
ARTIKA, I. M. (2010). Membrane Topology of Subunit 8 Variant of Yeast Saccharomyces cerevisiae Mitochondrial ATP Synthase. Microbiology Indonesia, 3(1), 7. https://doi.org/10.5454/mi.3.1.7
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