Fig. 3.

Equilibrium redox titration (22) of thiol/disulfide regulatory groups in the γ subunit of the chloroplast ATP synthase in wild type (WT) (closed squares) and gamera (opened triangles) (A). In situ fractional ATP synthase activity was estimated by probing ECS decay kinetics (ΔA₅₂₀) as described in the text. (n = 4–6). Detection of reduced (red) and oxidized (ox) γ subunit using gel shift assay, described in text (B). The redox states of γ₁ and γ₂ subunit thiols in wild type and gamera were visualized by AMS-labeling followed by SDS/PAGE and immnoblotting after treatment of leaf discs with water as control, MV, and reduced DTT under light (approximately 50 μmol photons m^-2 s^-1) or dark as described in Materials and Methods.