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.
Pubmed ID: 27986592 RIS Download
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.
A commercial antibody supplier and provider of various services.
View all literature mentionsPortal for deposition and retrieval of cryo electron microscopy (3DEM) density maps, atomic models, and associated metadata. Global resource for 3 Dimensional Electron Microscopy structure data archiving and retrieval, news, events, software tools, data standards, validation methods.
View all literature mentionsCommercial instrument and chemical vendor. Developer and manufacturer of specialized technological products for life science research and clinical diagnostics markets.
View all literature mentionsCommercial vendor and service provider of laboratory reagents and antibodies. Supplier of scientific instrumentation, reagents and consumables, and software services.
View all literature mentionsA commercial organization which provides assay technologies to isolate DNA, RNA, and proteins from any biological sample. Assay technologies are then used to make specific target biomolecules, such as the DNA of a specific virus, visible for subsequent analysis.
View all literature mentions