SNAP output for PDB entry 7r5v [SNAP web server]

PDB-id

7r5v; SNAP-derived features in text and JSON formats; DNAproDB

Class

cell cycle

Method

cryo-EM (4.55 Å)

Summary

Structure of the human ccan cenp-a alpha-satellite complex

Reference

Yatskevich S, Muir KW, Bellini D, Zhang Z, Yang J, Tischer T, Predin M, Dendooven T, McLaughlin SH, Barford D (2022): "Structure of the human inner kinetochore bound to a centromeric CENP-A nucleosome." Science, 376, 844-852. doi: 10.1126/science.abn3810.

Abstract

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.