Abstract
Nuclear Pore Complexes (NPCs) are portals for the nucleocytoplasmic transport of macromolecules. Here we provide the most comprehensive picture of the NPC in any organism to date. We resolved the structure of the inner ring at α-helical resolution with cryo-EM, providing insights into flexible connectors that tie together different structural and functional layers. Moreover, we show that some nucleoporins and soluble transport factors use similar interaction motifs which suggests that they coevolved from common ancestors. In addition, large scale pleomorphism contributes to three NPC variants that foreshadow functional adaptations at the nuclear periphery. Cryoelectron tomography extended these studies to provide a nearly complete model of the in situ NPC with a radially-expanded inner ring. This model includes nuclear basket anchors, connections to FG domains in the central channel and membrane contact sites. Together, the data highlight the structural redundancy and plasticity that underlies the function of this remarkable transport machine.
Competing Interest Statement
The authors have declared no competing interest.