Figure 3.

Characterization of the Synechocystis strains lacking Pam68, PsbH, or both of these proteins. A, Autotrophic growth of the wild-type and mutant strains on agar plates under various conditions. Growth for 5 d under normal light (40 μmol photons m⁻² s⁻¹), low light (10 μmol photons m⁻² s⁻¹), high light (400 μmol photons m⁻² s⁻¹), fluctuating dark/high light conditions (5 min dark, 5 min 400 μmol photons m⁻² s⁻¹), 18°C at 40 μmol photons m⁻² s⁻¹, and low nitrogen (0.1 mm NaNO₃). B, Levels of PsbH and Pam68 in the Δpam68 and ΔpsbH strains under normal light conditions. A comparable amount of Chl was loaded for each strain. C, Autotrophic growth of the pam68.f/Δpam68/ΔpsbH strain expressing the Pam68.f protein under the regulation of the psbAII promoter. D, Membranes, isolated from the wild-type and mutant strains grown as described in (A), were solubilized and separated by CN-PAGE. D/HL, dark/high light; HL, high light; LL, low light; NL, normal light; PSI[3], trimer of PSI; PSII[1], monomer of PSII; PSII[2], dimer of PSII.