Extended Data Fig. 4: Integrative modeling of the nexin-dynein regulatory complex (N-DRC) from C. reinhardtii and H. sapiens.
From: Axonemal structures reveal mechanoregulatory and disease mechanisms
a, Domain architecture of C. reinhardtii N-DRC subunits. b, Architecture of the N-DRC “bulb” in C. reinhardtii. c, Model of the N-DRC linker in the cryo-ET subtomogram average of the wildtype C. reinhartii axoneme (EMD-20338)27. Small differences between our model and the cryo-ET map are likely due to the loss of interactions with the neighboring doublet microtubule (DMT) in our splayed axoneme cryo-EM sample. d, Model of the N-DRC linker in the subtomogram average of the drc7 mutant axoneme (EMD-20339)27. The DRC7 subunit resides outside of the cryo-ET density, consistent with the loss of DRC7 in the mutant axonemes. Reduced density of the distal lobe, containing the C-termini of DRC9 and 10, suggest an altered or weakened interaction between DRC9/10 and the neighboring DMT in this mutant. e, Model of the N-DRC linker in the subtomogram average of the drc11 mutant axoneme (EMD-20340)27. Reduced density of the proximal lobe is consistent with the position of DRC11. f, Orthogonal views of the atomic model of human N-DRC. The bulb of human N-DRC (DRC1/9/10) is uncoupled from the baseplate unlike in C. reinhardtii. g, Interaction between the bulb and the N-terminal tail domain of DNAH7 (IDAe). h, Interaction between the 3-helix bundle of DRC3 and the linker of DNAH6 (IDAg).
