Figure 6.

PSII assembly in deap2 stalls at the RC stage exactly as in pam68.A) Analysis of the dynamics of photosystem II (PSII) assembly by labeling newly synthesized chloroplast proteins with [³⁵S] methionine and separating thylakoid complexes and denatured subunits by 2D blue-native (BN) gel electrophoresis. Leaf discs from wild type (WT), deap2-1 and pam68-2 were pulse labeled for 20 min in the presence of cycloheximide and thylakoids were directly processed, or leaf discs were first infiltrated again with nonradioactive methionine to be able to chase [³⁵S] methionine incorporation into higher PSII assembly stages [supercomplexes (PSII_SC), dimers (PSII_Di), monomers (PSII_Mon), reaction center (RC) and RC + CP47 (RC47)]. The arrow shows the transition from the RC to the RC47 assembly intermediates. Numbers right of the autoradiographs indicate molecular weight in kDa of protein standards. B) Scheme illustrating the transition from RC to RC47, of which efficient processing is dependent on the presence of both DEAP2 and PAM68.