What are the subunits of mitochondrial ATP synthase?

SouravOctober 11, 2024

Answer

Mitochondrial ATP synthase, also known as complex V, is composed of multiple subunits that are organized into two main functional domains: F₁ and Fₒ. Here is a breakdown of the subunits:

F₁ Domain

The F₁ domain is located in the mitochondrial matrix and is responsible for the synthesis of ATP from ADP and inorganic phosphate. It consists of the following subunits:

• Three α subunits: These are involved in the binding of ADP and phosphate.
• Three β subunits: These subunits contain the catalytic sites for ATP synthesis.
• One γ subunit: This subunit forms the central stalk and plays a crucial role in the rotation mechanism during ATP synthesis.
• One δ subunit: This subunit is part of the central stalk and helps stabilize the structure.
• One ε subunit: This subunit is also part of the central stalk and is involved in the regulation of ATP synthesis 2.

Fₒ Domain

The Fₒ domain is embedded in the inner mitochondrial membrane and is responsible for proton translocation. It consists of the following subunits:

• Subunit a: This subunit is involved in proton translocation across the membrane.
• Subunit c: This subunit forms a ring structure that rotates as protons pass through it, driving the rotation of the F₁ domain.
• Subunits b, d, and F₆: These subunits form the peripheral stalk and help anchor the F₁ domain to the membrane.
• OSCP (oligomycin sensitivity-conferring protein): This subunit is also part of the peripheral stalk and plays a role in the structural integrity of the complex.
• Accessory subunits (e, f, g, A6L): These additional subunits are present in the Fₒ domain and may have roles in assembly and stability 2.