Figure 4. Stt7 Cofractionates with the Cytochrome b ₆ f Complex.

(A) Thylakoid membranes from strains containing Stt7-HA and Stt7-HA with His-tagged Cytf (PetA-His) were solubilized with n-dodecyl-β-maltoside and fractionated by Ni-NTA chromatography. E1, E2 eluates (300 mM imidazole) were analyzed by PAGE and immunoblotting with the indicated antibodies. FT, flow-through; L, loading (10 mM imidazole); W1–W5, washes (20 mM imidazole).

(B) Stt7 interacts with the Rieske protein. GST and GST-Stt7 fusion protein were incubated separately with purified solubilized cytochrome b ₆ f complex from wild-type cells. The eluates (E) (100 mM DTT, 2% SDS) were analyzed by PAGE and immunoblotting with Rieske and Cytf antibodies. FT, flow-through; I, input; W1–W4, washes (PBS).