A New Model for Pore Formation by Cholesterol-Dependent Cytolysins
Figure 4
PFO Domain 4 and twist of Domain 2.
A. Variations in Domain 4 orientation for the PFO structures. Superposition is the same as in Figure 2A. Only five structures are shown for clarity: PFO I (blue); PFO IIB (dark blue); PFO IIID (cyan); PFO IIIA (orange); PFO IIIC (light orange). B. Coupling between PFO Domain 2 twist and Domain 4 orientation. Domain 3 is omitted for clarity. C. Twist values as a function of amino acid pairs for the continuous strands forming Domain 2. The seven crystal conformations are classified in two groups: conformations with partial loss of Domain 2/4 interface (interface ∼425 Å2; PFO IIIA & IIIC) in orange and all the others in blue (interface ∼605 Å2; Table 2). Minimum and maximum values are displayed for each group. D. Representative mainchains of Domain 2 β-sheet in stick representation. Blue: PFO I; orange: PFO IIIA. Superposition is the same as in Figure 2A. Numbers indicate amino-acid positions, dashed lines indicate mainchain hydrogen bonds.