Figure 4. Averaged projection maps of particles
present in F3 fraction of the sucrose density gradient (see
Fig. 1). (a) Top view of the PSI trimer after image-processing
600 particles. (b) Overlay of outline of the PSI trimer derived
from x-ray data of Jordan et al. (28). (c) Top view of a partially
degraded Pcb–PSII supercomplex after processing 681 particles.
(d) Overlay of outlines of the core dimer and CP43 (for each
Pcb subunit) derived from x-ray analysis of PSII isolated from
the cyanobacterium S. elongatus (27). (e) Top view of PSII core
dimers after processing 231 particles. ( f) Overlay of outline
of PSII core dimer from ref. 27. (Bar, 100 Å.)
