Action of Escherichia coli and human 5′ → 3′ exonuclease functions at incised apurinic/apyrimidinic sites in DNA

FEBS Letters

Price, Allan¹ 

[1] Imperial Cancer Research Fund, Clare Hall Laboratories, South Mimms, Herts., EN6 3LD, UK

关键词: Apurinic/apyrimidinic sites;    DNase IV;    DNA polymerase I;   

DOI  :  10.1016/0014-5793(92)80173-E

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The 5′ → 3′ exonuclease activity of E. coli DNA polymerase I and a related enzyme activity in mammalian cell nuclei. DNase IV, are unable to catalyse the excision of free deoxyribose-phosphate from apurinic/apyrimidinic (AP) sites incised by an AP endonuclease. Instead, the sugar phosphate residue is slowly released as part of a short oligonucleotide. These products have been characterised as dimers and trimers by comparison or their retention time on reverse-phase HPLC with reference compounds prepared by acid depurination of a dinucleotide, trinucleotide and tetranucleotide containing a 5′-terminal dAMP residue. The similar mode of action of these enzymes at 5′-incised AP sites provides an explanation for the minority of repair patches larger than one nucleotide observed when AP sites arc repaired by E. coli and mammalian cell extracts in vitro and strengthens the functional analogy between the two activities.

【 授权许可】

Unknown