The FA core complex contains a homo-dimeric catalytic module for the symmetric mono-ubiquitination of FANCI-FANCD2

DOI: 10.1016/j.celrep.2016.11.013

Authors: Paolo Swuec (The Francis Crick Institute) , Ludovic Renault (The Francis Crick Institute) , Aaron Borg (The Francis Crick Institute) , Fenil Shah (St. Vincent’s Institute of Medical Research) , Vincent J. Murphy (St. Vincent’s Institute of Medical Research) , Sylvie Van Twest (St. Vincent’s Institute of Medical Research) , Ambrosius P. Snijders (The Francis Crick Institute) , Andrew J. Deans (St. Vincent’s Institute of Medical Research) , Alessandro Costa (The Francis Crick Institute (LIF))
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Cell Reports , VOL 18 , PAGES 611 - 623

State: Published (Approved)
Published: January 2017
Diamond Proposal Number(s): 14266

Abstract: Activation of the main DNA interstrand crosslink repair pathway in higher eukaryotes requires mono-ubiquitination of FANCI and FANCD2 by FANCL, the E3 ligase subunit of the Fanconi anemia core complex. FANCI and FANCD2 form a stable complex; however, the molecular basis of their ubiquitination is ill defined. FANCD2 mono-ubiquitination by FANCL is stimulated by the presence of the FANCB and FAAP100 core complex components, through an unknown mechanism. How FANCI mono-ubiquitination is achieved remains unclear. Here, we use structural electron microscopy, combined with crosslink-coupled mass spectrometry, to find that FANCB, FANCL, and FAAP100 form a dimer of trimers, containing two FANCL molecules that are ideally poised to target both FANCI and FANCD2 for mono-ubiquitination. The FANCC-FANCE-FANCF subunits bridge between FANCB-FANCL-FAAP100 and the FANCI-FANCD2 substrate. A transient interaction with FANCC-FANCE-FANCF alters the FANCI-FANCD2 configuration, stabilizing the dimerization interface. Our data provide a model to explain how equivalent mono-ubiquitination of FANCI and FANCD2 occurs.

Journal Keywords: interstrand crosslink; Fanconi anemia; ubiquitin ligase; DNA repair; cryo-electron microscopy; mono-ubiquitination

Diamond Keywords: Enzymes

Subject Areas: Biology and Bio-materials, Chemistry

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

Added On: 21/04/2017 13:52

Documents:
S2211-1247(16)31554-6.pdf

Discipline Tags:

Health & Wellbeing Biochemistry Chemistry Structural biology Life Sciences & Biotech

Technical Tags:

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