FIGURE 7.

Models for the conformational changes that occur in Bax as a result of translocation and the inter-molecular contacts formed in the OMM. A, FRET efficiencies of Bax determined before translocation, taken from Table 1 and colored according to the bins as described in the legend to Fig. 3C, are illustrated on a proposed model of Bax where the C-terminal helix α9 is exposed. Of the five efficiencies, four correspond to distances that are consistent with the NMR solution structure of Bax. B, FRET efficiencies determined after translocation, taken from Table 1. C, two sites of inter-molecular contact are shown between the BH3 domains of separate Bax molecules as well as between C-terminal helices. The absence of FRET between helices α5 and α6 implies that an oligomeric rather than a dimer architecture is a reasonable model to satisfy these contacts.