Extended Data Fig. 6: RSP5 supports the radial spoke head.

a, RS head surface (viewed from the CP as shown at the bottom left) highlighting the RSP2, 3 and 5 protrusions that are linked to the core through the GAF domain of RSP2 and through RSP5. b, RSP5 has an aldo-keto reductase (AKR) fold and an extra coiled-coil positioned at the head surface (dashed oval in a). c, Expression of the head-neck proteins except for RSP5 resulted in purification of two complexes as shown by the two SEC peaks. The peak eluting earlier from the column (1) contains primarily RSP2, 3 and 23, whereas the second peak contains primarily RSP1, RSP4, RSP6, RSP9 and RSP10, as shown at the bottom by Coomassie-stained SDS-PAGE. d, Each of the complexes in c was expressed and purified separately. Top, Coomassie-stained SDS-PAGE of a complex composed of RSP2, RSP3 and RSP23 purified on an anion-exchange column. The three proteins, corresponding to most of the neck, are shown on the right as they appear in the head-neck structure. Bottom, Coomassie-stained SDS-PAGE of a complex composed of RSP1, RSP4, RSP6, RSP9 and RSP10 purified on a SEC column. The five proteins, corresponding to the center of the RS head, are shown on the right as they appear in the head-neck structure. Uncropped gel images are shown in Supplementary Fig. 1.