FEN1

Flap Endonucleases 1 (FEN1) is the recommended name for a class of nucleolytic enzymes that act towards 5’-3’ (in human beings), however it is also common to found other nomenclature such as “DNase IV”, “Flap structure-specific endonuclease 1” or “Maturation factor 1”. These enzymes are produced by E. Coli. FEN1 is a single polypeptide chain that contains about 380 amino acids and is implicated in biological processes, like DNA replication, recombination and repair. FEN1 splits 5’ flap single-stranded (ss) DNA at the single strand-double strand joint. It can as well displace and remove a defective nucleotide to a flap, in long-patch base excision repair. The endonuclease interacts with other nucleases and helicases that allow it to act efficiently on structured flaps. FEN1 is associated to FEN1 gene, wich one encodes a protein responsible for removing 5’ overhanging flaps in DNA repair and is required during the Okazaki fragment processing in DNA synthesis.