Protein Domain : Bacteriophage PBS2, uracil-glycosylase inhibitor IPR024062

Type	Homologous_superfamily
Description	DNA glycosylases excise damaged or unconventional bases in DNA and initiate the base excision repair (BER) pathway to maintain genomic integrity. Of these, uracil-DNA glycosylase (UDG) excises uracil from DNA by cleavage of the N-glycosidic bond between uracil and deoxyribose sugar. Uracil residues in DNA arise as a result of deamination of cytosine or incorporation of dUMP by DNA polymerase. Generally, the latter event is kept to a minimum by the presence of dUTPase which helps maintain a low level of dUTP. UDGs are inhibited by free uracil and some of its derivatives. Another category of UDG inhibitors is represented by Bacillus subtilis phage PBS1 and PBS2 encoded inhibitor protein Ugi and phage T5 induced proteins. PBS2 Ugi is a heat stable, acidic, low molecular weight protein of 9.5kDa, which interacts with UDG in a 1:1 molar stoichiometry to form a complex that does not dissociate under physiological conditions. This entry is represents the structural domain of the uracil-DNA glycosylase inhibitor protein from Bacillus phage PBS2 [ , , ]. The structure of the Escherichia coli uracil-DNA glycosylase complex with uracil-DNA glycosylase inhibitor (Ugi) protein from Bacillus phage PBS2 has been determined, Ugi folds into an α-β-alpha sandwich structure formed by five-stranded antiparallel β-strands and two helices [].
Short Name	Phage_PBS2_Ugi