The best substrate for the structure-specific endonuclease is a 3' flap followed by a nicked duplex, nicked three-way junctions, and nicked fourway junctions. The enzyme from Sulfolobus is only active in the presence of the sliding clamp PCNA (Proliferating-Cell-Nuclear-Antigen). It cleaves the replication fork or 3'-flap structures in the homodimeric form.
SsoXPF, xeroderma pigmentosum group F endonuclease, XPF endonuclease, XPF repair endonuclease, more
three different crystal forms of the enzyme are grown in trigonal, monoclinic and triclinic systems. The trigonal crystals diffract to 2.8 A and are grown in the presence of double-stranded DNA. Monoclinic crystals are grown without DNA and diffract to 3.2 A