Interaction of the Thermoplasma acidophilum A1A0-ATP synthase peripheral stalk with the catalytic domain.

The peripheral stalk of the archaeal ATP synthase (A1A0)-ATP synthase is formed by the heterodimeric EH complex and is part of the stator domain, which counteracts the torque of rotational catalysis. Here we used nuclear magnetic resonance spectroscopy to probe the interaction of the C-terminal domain of the EH heterodimer (E(CT1)H(CT)) with the N-terminal 23 residues of the B subunit (B(NT)). The data show a specific interaction of B(NT) peptide with 26 residues of the E(CT1)H(CT) domain, thereby providing a molecular picture of how the peripheral stalk is anchored to the A3B3 catalytic domain in A1A0.