Human FAN1 promotes strand incision in 5'-flapped DNA complexed with RPA.
Fanconi anaemia (FA) is a human infantile recessive disorder. Seventeen FA causal proteins cooperatively function in the DNA interstrand crosslink (ICL) repair pathway. Dual DNA strand incisions around the crosslink are critical steps in ICL repair. FA-associated nuclease 1 (FAN1) is a DNA structure-specific endonuclease that is considered to be involved in DNA incision at the stalled replication fork. Replication protein A (RPA) rapidly assembles on the single-stranded DNA region of the stalled fork. However, the effect of RPA on the FAN1-mediated DNA incision has not been determined. In this study, we purified human FAN1, as a bacterially expressed recombinant protein. FAN1 exhibited robust endonuclease activity with 5'-flapped DNA, which is formed at the stalled replication fork. We found that FAN1 efficiently promoted DNA incision at the proper site of RPA-coated 5'-flapped DNA. Therefore, FAN1 possesses the ability to promote the ICL repair of 5'-flapped DNA covered by RPA.
['Takahashi|Daisuke|D|', 'Sato|Koichi|K|', 'Hirayama|Emiko|E|', 'Takata|Minoru|M|', 'Kurumizaka|Hitoshi|H|']
D004247:DNA D004260:DNA Repair D004261:DNA Replication D004706:Endodeoxyribonucleases D004720:Endonucleases D005090:Exodeoxyribonucleases D005199:Fanconi Anemia D006801:Humans D064251:Multifunctional Enzymes D051716:Replication Protein A D015398:Signal Transduction
Fanconi anaemia structure-specific endonuclease replication protein A (RPA) DNA interstrand crosslinking repair Fanconi anaemia-associated nuclease 1 (FAN1)