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Structure of the Fanconi anaemia monoubiquitin ligase complex

DOI: 10.1038/s41586-019-1703-4 DOI Help

Authors: Shabih Shakeel (MRC Laboratory of Molecular Biology) , Eeson Rajendra (MRC Laboratory of Molecular Biology) , Pablo Alcon (MRC Laboratory of Molecular Biology) , Francis O'Reilly (Technische Universität Berlin) , Dror S. Chorev (University of Oxford) , Sarah Maslen (MRC Laboratory of Molecular Biology) , Gianluca Degliesposti (MRC Laboratory of Molecular Biology) , Christopher J. Russo (MRC Laboratory of Molecular Biology) , Shaoda He (MRC Laboratory of Molecular Biology) , Chris H. Hill (MRC Laboratory of Molecular Biology) , J. Mark Skehel (MRC Laboratory of Molecular Biology) , Sjors H. W. Scheres (MRC Laboratory of Molecular Biology) , Ketan J. Patel (MRC Laboratory of Molecular Biology) , Juri Rappsilber (Technische Universität Berlin; University of Edinburgh) , Carol V. Robinson (University of Oxford) , Lori A. Passmore (MRC Laboratory of Molecular Biology)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature , VOL 575 , PAGES 234 - 237

State: Published (Approved)
Published: November 2019
Diamond Proposal Number(s): 18091 , 17434

Abstract: The Fanconi anaemia (FA) pathway repairs DNA damage caused by endogenous and chemotherapy-induced DNA crosslinks, and responds to replication stress. Genetic inactivation of this pathway by mutation of genes encoding FA complementation group (FANC) proteins impairs development, prevents blood production and promotes cancer1,3. The key molecular step in the FA pathway is the monoubiquitination of a pseudosymmetric heterodimer of FANCD2–FANCI4,5 by the FA core complex—a megadalton multiprotein E3 ubiquitin ligase6,7. Monoubiquitinated FANCD2 then recruits additional protein factors to remove the DNA crosslink or to stabilize the stalled replication fork. A molecular structure of the FA core complex would explain how it acts to maintain genome stability. Here we reconstituted an active, recombinant FA core complex, and used cryo-electron microscopy and mass spectrometry to determine its structure. The FA core complex comprises two central dimers of the FANCB and FA-associated protein of 100 kDa (FAAP100) subunits, flanked by two copies of the RING finger subunit, FANCL. These two heterotrimers act as a scaffold to assemble the remaining five subunits, resulting in an extended asymmetric structure. Destabilization of the scaffold would disrupt the entire complex, resulting in a non-functional FA pathway. Thus, the structure provides a mechanistic basis for the low numbers of patients with mutations in FANCB, FANCL and FAAP100. Despite a lack of sequence homology, FANCB and FAAP100 adopt similar structures. The two FANCL subunits are in different conformations at opposite ends of the complex, suggesting that each FANCL has a distinct role. This structural and functional asymmetry of dimeric RING finger domains may be a general feature of E3 ligases. The cryo-electron microscopy structure of the FA core complex provides a foundation for a detailed understanding of its E3 ubiquitin ligase activity and DNA interstrand crosslink repair.

Journal Keywords: Cancer; Cryoelectron microscopy; DNA damage response; Mass spectrometry; Ubiquitylation

Diamond Keywords: Fanconi Anaemia (FA)

Subject Areas: Biology and Bio-materials

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

Added On: 28/11/2019 12:15

Discipline Tags:

Non-Communicable Diseases Health & Wellbeing Cancer Genetics Structural biology Life Sciences & Biotech

Technical Tags:

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