ATP15 encodes the epsilon subunit of mitochondrial ATP synthase (1). The ATP synthase complex utilizes proton motive force to generate ATP from ADP and P_i (3). The structure of this enzyme complex is highly conserved among diverse organisms and consists of two major components, soluble F₁ and membrane-bound F₀, each of which contains many subunits. F₁ and F₀ are connected, both functionally and physically, via two additional multi-subunit structures, the central stalk and the stator stalk. The epsilon subunit is a component of the central stalk, which, like a rotor shaft, transmits the movement of the F₀ proton pump to the catalytic core of F₁. Unlike many ATP synthase subunits, the mitochondrial epsilon subunit does not have a bacterial homolog. The bacterial subunit named "epsilon" is homologous to mitochondrial "delta" (Atp16p) (3 and 4 and references therein).

Although ATP15 is essential for ATP synthase function, it is not essential for life in yeast. Deletion of ATP15, like deletions in many genes necessary for the function or maintenance of mitochondria, leads to a "petite" phenotype that is slow-growing and unable to survive on nonfermentable carbon sources (1).

General ATP synthase structure and function are reviewed in references 3 and 4. For a review that is specific to yeast, see reference 5).

Last updated: 2001-01-16