Architecture and DNA recognition elements of the Fanconi anemia FANCM-FAAP24 complex.
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)2 domain is buried, whereas the FAAP24 (HhH)2 domain 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 FANCMCTD by 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.
Structural Biology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK.
Rachel
R
Coulthard
Andrew J
AJ
Deans
Paolo
P
Swuec
Maureen
M
Bowles
Alessandro
A
Costa
Stephen C
SC
West
Neil Q
NQ
McDonald
D000255:Adenosine Triphosphate / Q000737:chemistry; D020134:Catalytic Domain; D002470:Cell Survival / Q000187:drug effects; D056831:Coordination Complexes / Q000737:chemistry; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D004249:DNA Damage; D004265:DNA Helicases / Q000737:chemistry* / Q000378:metabolism; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D051856:Fanconi Anemia Complementation Group Proteins; D055785:Gene Knockdown Techniques; D057809:HEK293 Cells; D006801:Humans; D006868:Hydrolysis; D016685:Mitomycin / Q000494:pharmacology; D008958:Models, Molecular; D009153:Mutagens / Q000494:pharmacology; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry; D011485:Protein Binding; D017433:Protein Structure, Secondary; D034741:RNA, Small Interfering / Q000235:genetics
D056831:Coordination Complexes; D004268:DNA-Binding Proteins; C518296:FAAP24 protein, human; D051856:Fanconi Anemia Complementation Group Proteins; D009153:Mutagens; D009841:Oligonucleotides; D034741:RNA, Small Interfering; D016685:Mitomycin; D000255:Adenosine Triphosphate; C518295:FANCM protein, human; D004265:DNA Helicases