Subunit F modulates ATP binding and migration in the nucleotide-binding subunit B of the A[subscript 1]A[subscript O] ATP synthase of Methanosarcina mazei Gö1
The interaction of the nucleotide-binding subunit B with subunit F is essential in coupling of ion pumping and ATP synthesis in A[subscript 1]A[subscript O] ATP synthases. Here we provide structural and thermodynamic insights on the nucleotide binding to the surface of subunits B and F of Methanosar...
| Main Authors: | , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
Springer US
2017
|
| Online Access: | http://hdl.handle.net/1721.1/106217 |
| Summary: | The interaction of the nucleotide-binding subunit B with subunit F is essential in coupling of ion pumping and ATP synthesis in A[subscript 1]A[subscript O] ATP synthases. Here we provide structural and thermodynamic insights on the nucleotide binding to the surface of subunits B and F of Methanosarcina mazei Gö1 A[subscript 1]A[subscript O] ATP synthase, which initiated migration to its final binding pocket via two transitional intermediates on the surface of subunit B. NMR- and fluorescence spectroscopy as well as ITC data combined with molecular dynamics simulations of the nucleotide bound subunit B and nucleotide bound B-F complex in explicit solvent, suggests that subunit F is critical for the migration to and eventual occupancy of the final binding site by the nucleotide of subunit B. Rotation of the C-terminus and conformational changes in subunit B are initiated upon binding with subunit F causing a perturbation that leads to the migration of ATP from the transition site 1 through an intermediate transition site 2 to the final binding site 3. This mechanism is elucidated on the basis of change in binding affinity for the nucleotide at the specific sites on subunit B upon complexation with subunit F. The change in enthalpy is further explained based on the fluctuating local environment around the binding sites. |
|---|