Spontaneous deamination of cytosine results in a premutagenic G: U mismatch that may
result in a GC→ AT transition during replication. The human UNG-gene encodes the major
uracil-DNA glycosylase (UDG or UNG) which releases uracil from DNA, thus, initiating base
excision repair to restore the correct DNA sequence. Bacterial and yeast mutants lacking the
homologous UDG exhibit elevated spontaneous mutation frequencies. Hence, mutations in
the human UNG gene could presumably result in a mutator phenotype. We screened all …