Article Metrics


Online attention

Structure of the inner kinetochore CCAN complex assembled onto a centromeric nucleosome

DOI: 10.1038/s41586-019-1609-1 DOI Help

Authors: Kaige Yan (MRC Laboratory of Molecular Biology) , Jing Yang (MRC Laboratory of Molecular Biology) , Ziguo Zhang (MRC Laboratory of Molecular Biology) , Stephen H. Mclaughlin (MRC Laboratory of Molecular Biology) , Leifu Chang (MRC Laboratory of Molecular Biology) , Domenico Fasci (University of Utrecht) , Ann E. Ehrenhofer-Murray (Humboldt-Universit├Ąt zu Berlin) , Albert J. R. Heck (University of Utrecht) , David Barford (MRC Laboratory of Molecular Biology)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature , VOL 574 , PAGES 278 - 282

State: Published (Approved)
Published: October 2019
Diamond Proposal Number(s): 13262 , 13708 , 17434

Open Access Open Access

Abstract: In eukaryotes, accurate chromosome segregation in mitosis and meiosis maintains genome stability and prevents aneuploidy. Kinetochores are large protein complexes that, by assembling onto specialized Cenp-A nucleosomes1,2, function to connect centromeric chromatin to microtubules of the mitotic spindle3,4. Whereas the centromeres of vertebrate chromosomes comprise millions of DNA base pairs and attach to multiple microtubules, the simple point centromeres of budding yeast are connected to individual microtubules5,6. All 16 budding yeast chromosomes assemble complete kinetochores using a single Cenp-A nucleosome (Cenp-ANuc), each of which is perfectly centred on its cognate centromere7-9. The inner and outer kinetochore modules are responsible for interacting with centromeric chromatin and microtubules, respectively. Here we describe the cryo-electron microscopy structure of the Saccharomyces cerevisiae inner kinetochore module, the constitutive centromere associated network (CCAN) complex, assembled onto a Cenp-A nucleosome (CCAN-Cenp-ANuc). The structure explains the interdependency of the constituent subcomplexes of CCAN and shows how the Y-shaped opening of CCAN accommodates Cenp-ANuc to enable specific CCAN subunits to contact the nucleosomal DNA and histone subunits. Interactions with the unwrapped DNA duplex at the two termini of Cenp-ANuc are mediated predominantly by a DNA-binding groove in the Cenp-L-Cenp-N subcomplex. Disruption of these interactions impairs assembly of CCAN onto Cenp-ANuc. Our data indicate a mechanism of Cenp-A nucleosome recognition by CCAN and how CCAN acts as a platform for assembly of the outer kinetochore to link centromeres to the mitotic spindle for chromosome segregation.

Subject Areas: Biology and Bio-materials, Chemistry

Diamond Offline Facilities: Electron Bio-Imaging Centre (eBIC)
Instruments: Krios I-Titan Krios I at Diamond , Krios III-Titan Krios III at Diamond , Krios V-Titan Krios V at Diamond

Added On: 19/03/2020 13:10

Discipline Tags:

Biochemistry Chemistry Structural biology Life Sciences & Biotech

Technical Tags:

Microscopy Electron Microscopy (EM) Cryo Electron Microscopy (Cryo EM)