discontinuous dna replication has been examined in the absence of uracil excision by comparing okazaki fragments in strains that are defective in dna polymerase i ( pola ( - ) ) and pola ( - ) strains that are also defective in uracil n-glycosidase , an enzyme required for the excision-repair of uracil in dna ( pola ( - ) ung ( - ) ) .
C0598312
dna replication
C0012854
dna