Fig. 5: Structures of PFR-axoneme connectors (PACs). | Cell Discovery

Fig. 5: Structures of PFR-axoneme connectors (PACs).

From: Structure of the trypanosome paraflagellar rod and insights into non-planar motility of eukaryotic cells

Fig. 5: Structures of PFR-axoneme connectors (PACs).

a A schematic with an enlarged inset illustrating the locations of the four PACs in the T. brucei flagellum. The colored boxes enclosing each PAC approximate the regions used for obtaining sub-tomographic averages detailed in b–e. b Details and dynamics of the PAC7 structure. A 10nm-thick longitudinal density slice (b2) from the location indicated by the blue line in B1 shows that PAPs have variable sizes (orange arrows), are connected to DMT7 by globular densities (red dots) and are separated by variable gaps (yellow arrowheads). Three surface views of the averaged PAC7 structure (b3) show its PAP, baseplate, and connecting filaments. Four PAC7 structures are montaged (b4) according to the locations in b2 to illustrate connectivity. Schematics in b5 and b6 depict dimensions of PAC7 components (b5), illustrate how PAPs interact with DMT7 through globular densities (red dots) (b6), and that sliding (double-headed arrow) might produce the heterogeneity in size and spacing observed for PAPs (b6). c Zoomed in surface views of the PAC5 region showing details and interconnections. Each panel is a montage of five sub-tomographic averages: the 96 nm averaged axoneme (gray), 54 nm averaged PFR proximal zone (light purple), PAC5-1 (green), 5-2 (yellow), and 5-3 (blue). d Two orthogonal zoomed in surface views (d1 and d2) and schematics (d3) of the PAC4 region, illustrating periodicities of OAD, PACs, and the α/β-tubulin dimer. Panels d1 and d2 are each a montage of three sub-tomographic averages: the 96 nm averaged axoneme (gray) and the 54 nm averaged PFR proximal zone (light purple) and PAC4 (dark purple). e Zoomed in surface views of the DMT6 region showing details. Panel e1 is a montage of four sub-tomographic averages: the 96 nm averaged axoneme (gray), the 8 nm averaged DMT6-MOP-B1,2 (orange), and the 54 nm averaged PFR proximal zone (light purple) and PAC5-1 (green). Panel e2 is a montage of two sub-tomographic averages: the 96 nm averaged axoneme and the 8 nm averaged DMT6-MOP-B1,2 (orange).

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