Figure 3.

Structure of Rsbc₁/azo with ISP–ED disordered. A, two cyt b subunits are shown as green ribbons containing the b_H and b_L heme groups. Azoxystrobin is shown as a CPK model and lipid molecules as ball-and-stick models. The two cyt c₁ subunits with covalently linked c-type hemes are shown in blue. The bound Sr²⁺ ions (silver spheres) stem from a crystallization additive. Both yellow ribbon models of the iron–sulfur protein are highly disordered and are shown in a position that places their Fe₂S₂ clusters in or near a position with detectable anomalous signal from their iron atoms. The parallel horizontal lines delineate the boundary of the membrane bilayer. B, electron density for the Rsbc₁/azo dimer with cyt b in red, cyt c₁ in blue, and ISP in yellow. Although the N-terminal helix of ISP has a good electron density, the head domain is largely disordered.