Question

The conformation(s) of the catalytic sites in ATP synthase ___________________. have different substrate binding affinities have different product binding affinities at any one time are present in different conformations from the other catalytic sites pass sequentially through three different conformations All of these are correct.

Answer 1

All of these are correct.

Step-by-step explanation:

ATP synthase is an F type pump with two multiprotein complexes. One of the protein complexes has three types of integral membrane proteins a, b and c while another protein complex has five polypeptides with distinct composition. It has three copies of each alpha and beta subunits and one copy of each gamma, delta and epsilon subunits.

The beta subunits have a binding site for ADP and Pi and catalyze ATP synthesis. Rotation of gamma subunits relative to the fixed alpha and beta subunits causes the catalytic binding site of each beta subunit to obtain either of three conformational states.

An O state has a high low affinity for ATP, ADP, and Pi while L state has a high affinity for ADP and Pi. The T state binds to ADP and Pi tightly to facilitate the formation of ATP. The T state also has a high affinity for ATP.