Fig. 6: Structure of the central ring scaffold of X. laevis NPC.

a Overall structure of the central ring scaffold (CR/IR/NR) of X. laevis NPC. Combining the atomic models of the CR²⁴ and IR,²⁵ we generated a composite model of the central ring scaffold of X. laevis NPC. Shown here are two perpendicular views. All nucleoporins are color-coded and tabulated below the images. The X. laevis NPC has outer and inner diameters of ~130 nm and ~45 nm, respectively. b Overall structure of one subunit of the central ring scaffold. Two perpendicular views are shown, with nucleoporins color-coded. The CR and NR subunits are placed symmetrically on the cytoplasmic and nuclear sides, respectively, of the symmetric IR subunit. The subunit is anchored on the NE mainly through NDC1 and the β-propeller domains from Nup155, Nup160, Nup133 and ELYS. The CR and NR are linked to the IR mainly through two molecules of Nup155. c A close-up view on the interface between the linker Nup155 and CR components. The C-terminal helices of linker Nup155 are sandwiched by inner Nup160 and inner Nup205 from the CR subunit. d A close-up view on the interface between linker Nup155 and NR components. The C-terminal helices of linker Nup155 contact the middle portion of the α-helical domain of inner Nup160 from the NR.