Nuclear pore complexes (NPCs) are >100 MDa structures composed of protein called nucleoporins. NPCs are the central gatekeepers of nucleocytoplasmic transport and control all macromolecular exchange between the two compartments. The architecture of the NPC central channel was widely debated at the time and multiple structures of incomplete fragments of the channel nucleoporins were published before that suggested extensive oligomerization of these proteins. We used nanobodies as crystallization chaperones to obtain the high resolution structure of a more complete version of the vertebrate coiled-coil Nup62-Nup58-Nup54 complex that lines the central NPC channel. Our structure directly showed a 1:1:1 stoichiometry of the heterotrimer and refuted prior central channel models based on oligomerization.