Exodeoxyribonuclease III-like (IPR037493)

Short name: ExoIII-like

Overlapping homologous superfamilies

Family relationships


This entry includes Escherichia coli ExoIII and related proteins. They are AP endonucleases that belong to the large EEP (exonuclease/endonuclease/phosphatase) superfamily. ExoIII removes the damaged DNA at cytosines and guanines by cleaving on the 3'-side of the AP site by a beta-elimination reaction. It exhibits 3'-5'-exonuclease, 3'-phosphomonoesterase, 3'-repair diesterase and ribonuclease H activities [PMID: 7885481].

Cellular DNA is spontaneously and continuously damaged by environmental and internal factors such as X-rays, UV light and agents such as the antitumor drugs bleomycin and neocarzinostatin or those that generate oxygen radicals. Apurinic/apyrimidinic (AP) sites form both spontaneously and as highly cytotoxic intermediates in the removal of the damaged base by the base excision repair (BER) pathway. DNA repair at the AP sites is initiated by specific endonuclease cleavage of the phosphodiester backbone. Such endonucleases are also generally capable of removing blocking groups from the 3'terminus of DNA strand breaks. AP endonucleases can be classified into two families on the basis of sequence similarity and structure. ExoIII belongs to family 1 [PMID: 7661852].

GO terms

Biological Process

GO:0006281 DNA repair

Molecular Function

GO:0008853 exodeoxyribonuclease III activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.