Figure 1: Composition of the FFC.

(a) Gel filtration analysis (Superose 6) of FRQ (108 kDa) and FRH (125 kDa) from wild-type (WT) and frq¹⁰ strains. The elution of molecular mass standards is indicated. (b) Prediction of coiled-coils (Expasy) in FRQ (989 amino acid residues). Dimerization/oligomerization of FRQ is dependent on the coiled-coil domain¹⁹. The location and composition of the NLS are indicated. (c) FRQΔNLS forms a stable complex with FRH. FRH from WT and frqΔNLS strains was immunoprecipitated with affinity-purified antibodies. Western blots were decorated with FRQ antibody to detect co-immunoprecipitation. (d) FRQΔNLS²⁰ does not form oligomeric complexes. Gel filtration (Superose 6) analysis of native protein extracts of light-grown WT and frqΔNLS strains. Densitometric quantification of western blots (Supplementary Fig. 1c) showing the elution profiles of FRQ and FRQΔNLS. (e) In vitro reconstitution of the FFC. Recombinant FRQ and FRHΔN (Supplementary Fig. 1d) form a ~670-kDa assembly with approximately 1:1 stoichiometry. Gel filtration (Superose 6) and SDS-PAGE analysis of the elution profiles of FRQ and FRHΔN are shown.