28OP

Structure of the human inner kinetochore CCAN and CENP-C bound to DNA

Summary for 28OP

• Entry DOI: 10.2210/pdb28op/pdb
• EMDB information: 56683
• Descriptor: Centromere protein M, Centromere protein I, Centromere protein K, ... (18 entities in total)
• Functional Keywords: centromeres, kinetochores, cell cycle
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 18
• Total formula weight: 720303.71

Authors

Yu, C.,Barford, D. (deposition date: 2026-02-11, release date: 2026-05-20)

Primary citation

Yu, C.,Muir, K.W.,Yang, J.,Zhang, Z.,McLaughlin, S.H.,Barford, D.
Models for the architecture of the human inner kinetochore on centromeric alpha-satellite CENP-A nucleosome arrays.
Nat Commun, 2026

PubMed Abstract: Human kinetochores assemble onto centromeric DNA comprising repetitive arrays of the 171 bp α-satellite sequence. To understand the higher-order architecture of the inner kinetochore assembled onto α-satellite arrays, we show cryo-EM structures of CCAN with free DNA, and α-satellite repeat monomers and dimers with CENP-A nucleosomes. CCAN bound to free DNA and a monomeric CENP-A nucleosome engages 70 bp of DNA comprising 30 bp of an upstream α-satellite repeat. This upstream DNA interacts with the histone-fold domain subunits of the CENP-TWSX module in a manner resembling how nucleosomes wrap DNA gyres. A complex of CCAN assembled onto a dimeric α-satellite repeat with two CENP-A nucleosomes shows that CCAN can only be accommodated on the linker DNA by unwrapping DNA from both the CENP-TWSX module and the upstream nucleosome. We discuss the implications of these results for models of CCAN assembly on arrays of α-satellite chromatin containing CENP-A nucleosomes.

PubMed: 42120391
DOI: 10.1038/s41467-026-72856-0

Experimental method

ELECTRON MICROSCOPY (2.7 Å)