Fanconi anemia (FA) is a disorder associated with a failure in DNA repair. FANCM (defective in FA complementation group M) and its partner FAAP24 target other FA proteins to sites of DNA damage. FANCM-FAAP24 is related to XPF/MUS81 endonucleases but lacks endonucleolytic activity. We report a structure of an FANCM C-terminal fragment (FANCMCTD) bound to FAAP24 and DNA. This S-shaped structure reveals the FANCM (HhH)2domain is buried, whereas the FAAP24 (HhH)2domain engages DNA. We identify a second DNA contact and a metal center within the FANCM pseudo-nuclease domain and demonstrate that mutations in either region impair double-stranded DNA binding in vitro and FANCM-FAAP24 function in vivo. We show the FANCM translocase domain lies in proximity to FANCMCTDby electron microscopy and that binding fork DNA structures stimulate its ATPase activity. This suggests a tracking model for FANCM-FAAP24 until an encounter with a stalled replication fork triggers ATPase-mediated fork remodeling.
|Titolo:||Architecture and DNA recognition elements of the fanconi anemia FANCM-FAAP24 complex|
|Parole Chiave:||Adenosine Triphosphate; Catalytic Domain; Cell Survival; Coordination Complexes; Cryoelectron Microscopy; Crystallography, X-Ray; DNA Damage; DNA Helicases; DNA Repair; DNA-Binding Proteins; Gene Knockdown Techniques; HEK293 Cells; Humans; Hydrolysis; Mitomycin; Models, Molecular; Mutagens; Nucleic Acid Conformation; Oligonucleotides; Protein Binding; Protein Structure, Secondary; RNA, Small Interfering; Structural Biology; Molecular Biology|
|Settore Scientifico Disciplinare:||Settore BIO/10 - Biochimica|
|Data di pubblicazione:||3-set-2013|
|Digital Object Identifier (DOI):||10.1016/j.str.2013.07.006|
|Appare nelle tipologie:||01 - Articolo su periodico|