Figure 9.

Postulated roles of Atp23p and Atp10p in assembly of subunit 6. The top panel shows processing of the subunit 6 precursor by Atp23p and its further interaction with the subunit 9 ring. Although processing of the subunit 6 precursor is shown to precede its interaction with the subunit 9 ring, the order could be reversed or the two events could occur concurrently. Degradation of the subunit 6 precursor as a result of the absence of Atp23p is illustrated in the second panel from the top. The third panel shows that in the presence of Atp23p with the E→Q mutation, processing of the precursor is prevented but the precursor is still able to interact with the subunit 9 ring. In the bottom panel the absence of Atp10 allows some of the precursor to be processed and assembled but most of subunit 6 is degraded. Although this model shows an interaction of Atp23p and Atp10p, there is no experimental evidence to support this at present.