biostudies-literatureYatskevich SCancer Research UKMedical Research Council844-852https://www.ebi.ac.uk/biostudies/studies/S-EPMC7612757biostudies-literatureUnknown376(6595)Kinetochores assemble onto specialized centromeric CENP-A (centromere protein A) nucleosomes (CENP-A^Nuc) to mediate attachments between chromosomes and the mitotic spindle. We describe cryo-electron microscopy structures of the human inner kinetochore constitutive centromere associated network (CCAN) complex bound to CENP-A^Nuc reconstituted onto α-satellite DNA. CCAN forms edge-on contacts with CENP-A^Nuc, and a linker DNA segment of the α-satellite repeat emerges from the fully wrapped end of the nucleosome to thread through the central CENP-LN channel that tightly grips the DNA. The CENP-TWSX histone-fold module further augments DNA binding and partially wraps the linker DNA in a manner reminiscent of canonical nucleosomes. Our study suggests that the topological entrapment of the linker DNA by CCAN provides a robust mechanism by which kinetochores withstand both pushing and pulling forces exerted by the mitotic spindle.Science (New York, N.Y.)Structure of the human inner kinetochore bound to a centromeric CENP-A nucleosome.PMC761275724307MC_UP_1201/6DRCRPG-Jun22\100004MC_U105184326Tischer TYang JPredin MZhang ZBellini DYatskevich SMuir KWMcLaughlin SHDendooven TBarford DfalseStructure of the human inner kinetochore bound to a centromeric CENP-A nucleosome.Kinetochores assemble onto specialized centromeric CENP-A (centromere protein A) nucleosomes (CENP-A^Nuc) to mediate attachments between chromosomes and the mitotic spindle. We describe cryo-electron microscopy structures of the human inner kinetochore constitutive centromere associated network (CCAN) complex bound to CENP-A^Nuc reconstituted onto α-satellite DNA. CCAN forms edge-on contacts with CENP-A^Nuc, and a linker DNA segment of the α-satellite repeat emerges from the fully wrapped end of the nucleosome to thread through the central CENP-LN channel that tightly grips the DNA. The CENP-TWSX histone-fold module further augments DNA binding and partially wraps the linker DNA in a manner reminiscent of canonical nucleosomes. Our study suggests that the topological entrapment of the linker DNA by CCAN provides a robust mechanism by which kinetochores withstand both pushing and pulling forces exerted by the mitotic spindle.2022-01-01T00:00:00Z2022 May2025-04-04T02:25:24.342Z2025-02-19T01:23:40.299ZS-EPMC76127573542089110.1126/science.abn3810