Figure 5.

Ratios of complexes that tend to associate with other complexes. After normalizing protein content by the GFP content in individual pull-down samples, the percentages of the photosynthetic complexes that associate with other complexes were calculated by dividing the sum of the subunit abundance of a specific photosynthetic complex detected in the pull-down samples for another GFP-labelled complex with the sum of the abundance of the same photosynthetic complex from its corresponding GFP-labelled pull-down sample. For example, the ratio of PSII that associates with PSI is determined by the abundance of PSII in the PSI–GFP pull-down sample divided by the PSII content in the PSII–GFP pull-down sample. The results showed that PSI and PSII possess a higher preference to form supercomplexes than with others (1.72% PSI are associated with PSII, n = 3; 9.9% PSII are associated with PSI, n = 3) (a,b). Cyt b₆f has a higher preference to bind with PSI (4.1%, n = 3) than PSII (2.0%, n = 3) (c). All PSI, PSII and Cyt b₆f have a low preference to interact with ATPases, while ATPases exhibit relatively similar tendencies to associate with the other three complexes (d). Box plots display the median (line), the average (cross), the interquartile range (box), and the maximum and minimum (whiskers). Statistical analysis was performed using Student's t-test. *0.01 < p < 0.05; **0.001 < p < 0.01; n.s., not significant.