摘要We report the characterization of a uraciI-DNA glycosylase(UDG) from the hyperthermophilic archaea Pyrococcus furiosus(P.furiosus).P.furiosus UDG(PfUDG) has high sequence similarity to the families IV and V UDGs(thermostable UDG family and PaUDG-b family).PfUDG excises uracil from various DNA substrates with the following order:U/T≈U/C＞U/G≈U/AP≈U/-＞U/U≈U/I≈U/A.The optimal temperature and pH value for uracil excision by PfUDG are 70 °C and 9.0,respectively.The removal of U is inhibited by the divalent ions of Fe,Ca,Zn,Cu,Co,Ni and Mn,as well as a high concentration of NaCI.The phosphorothioates near uracil strongly inhibit the excision of uracil by PfUDG.Interestingly,pfuDNA(Pyrococcusfuriosus DNA) polymerase,which tightly binds the uracil-carrying oligonucleotide,does not inhibit the excision by PfUDG,suggesting PfUDG in vivo functions as the repair enzyme to excise uracil damage in genome.