Figure 4.

LHCII interactions control the partitioning of LHCII between the grana and the stromal lamellae and affect the organization of PSII but not PSI. (A) The percentage of PSI in complex with LHCII with varying strength of the PSI-LHCII interaction is shown (dashed lines show experimentally observed range of the percentage of PSI-LHCII). (B) The percentage of LHCII in the stromal lamellae with varying strength of the PSI-LHCII interaction is shown. (C) The percentage of LHCII complexes partitioned into the stromal lamellae in state I (blue), state II (red), and with no interactions present (random, gray) is shown. (D) Shown is the percentage of PSI in complex with LHCII (defined as LHCII ≤1 nm from binding site) in state I, state II, and random simulations. (E) Shown is the percentage of PSI in complex with LHCII in state II when LHCII is or is not allowed to migrate between the grana and the stromal lamellae. (F) The percentage of LHCII complexes partitioned into the stromal lamellae and the percentage of PSI in complex with LHCII after the density of the PSI in the stromal lamellae was decreased by half (this was achieved by increasing the area of the stromal lamellae). Error bars in (A)–(F) indicate mean ± standard deviation. (G) Shown is the nearest-neighbor distribution (center-to-center distances) of PSII-LHCII supercomplexes in state I (blue circles) and state II (red squares). The two modes arising in state I are indicated by blue arrows. (H) The nearest-neighbor distribution (center-to-center distances) of PSI in state I and state II is shown. (I) The nearest-neighbor distribution (center-to-center distances) of LHCII in state I and state II is shown. To see this figure in color, go online.