Model for assembly of F1Fo-ATPase at 37°C. The inner membrane (IM) is shown with the intermembrane space above the membrane and the matrix below. One subunit of the Yme1 and Yta10/12 complexes is shown. A. Assembly of F1. Yme1 interacts genetically with Hsc82 or Hsp82 to which Atp2 is bound with Atp11 as chaperone. Yta10/12 interacts in an unknown way with the central stalk to which only Hsc82 is bound. Atp1 is bound to chaperone Atp12, which in turn is bound to Fmc1. Assembly of Atp1 and Atp2 around Atp3 begins with interaction of Atp3 with Atp1 displacing Atp12 and Fmc1. As assembly proceeds Atp11, Atp12, and Yta10/12 are displaced and Hsc82 is displaced from Atp3 to produce B. The interaction of Yme1 with Atp2 via Hsc82/Hsp82 remains while F1 associates with oligo-Atp9 that has been formed with assistance from Atp25 to form C. F1-Atp9 associates with Atp8 and the peripheral stalk complex (only Atp4 and Atp5 are shown). Yme1 and Hsc82/Hsp82 are displaced to form D. Atp6 is incorporated with assistance from Atp10, Atp23 and Oxa1 to produce F1F0-ATPase, E.