1. Cryo electron tomography with volta phase plate reveals novel structural foundations of the 96-nm axonemal repeat in the pathogen Trypanosoma brucei.
- Author
-
Imhof, Simon, Zhang, Jiayan, Wang, Hui, Bui, Khanh Huy, Nguyen, Hoangkim, Atanasov, Ivo, Hui, Wong H, Yang, Shun Kai, Zhou, Z Hong, and Hill, Kent L
- Subjects
Trypanosoma brucei brucei ,Protozoan Proteins ,Imaging ,Three-Dimensional ,Cryoelectron Microscopy ,Protein Binding ,Axoneme ,Electron Microscope Tomography ,axoneme ,cell biology ,cilium ,dynein ,infectious disease ,microbiology ,motility ,parasite ,trypanosome ,Vector-Borne Diseases ,Infectious Diseases ,2.2 Factors relating to the physical environment ,Infection ,Biochemistry and Cell Biology - Abstract
The 96-nm axonemal repeat includes dynein motors and accessory structures as the foundation for motility of eukaryotic flagella and cilia. However, high-resolution 3D axoneme structures are unavailable for organisms among the Excavates, which include pathogens of medical and economic importance. Here we report cryo electron tomography structures of the 96-nm repeat from Trypanosoma brucei, a protozoan parasite in the Excavate lineage that causes African trypanosomiasis. We examined bloodstream and procyclic life cycle stages, and a knockdown lacking DRC11/CMF22 of the nexin dynein regulatory complex (NDRC). Sub-tomogram averaging yields a resolution of 21.8 Å for the 96-nm repeat. We discovered several lineage-specific structures, including novel inter-doublet linkages and microtubule inner proteins (MIPs). We establish that DRC11/CMF22 is required for the NDRC proximal lobe that binds the adjacent doublet microtubule. We propose that lineage-specific elaboration of axoneme structure in T. brucei reflects adaptations to support unique motility needs in diverse host environments.
- Published
- 2019