Figure 5. The structure of the largest Pcb–PSII
supercomplex isolated from Prochloron, incorporating
the x-ray structures of the PSII core dimer and CP43 of S. elongatus
(27), emphasizing the positioning of the Chl molecules (shown
in light green) and transmembrane helices. CP43 is used as a
model for the Pcb subunits with transmembrane helices shown
in blue and with helices 5 and 6 facing the PSII core dimer.
In the case of the PSII core dimer, the color coding for the
transmembrane helices is: yellow, D1 protein; orange, D2 protein;
red,
CP47; dark green, CP43; cyan, cytochrome b559; purple, low molecular
weight subunits. (Bar, 100 Å.)
