Movie 3

shows the location of the FAP70 N-terminus at the base of the C2a projection. Surface rendering of the difference map between WT and fap70::FAP70-N-BCCP-HA axonemes treated with streptmp4din and biotinylated cytochrome c put the densities of the streptmp4din label (red dots) adjacent to the base of C2a, beneath the arcade of C2e, with a repeat of 16 nm. The video begins and ends with a cross-sectional view of the CA as seen from the base of the flagellum.