3'-5' exonuclease domain (IPR002562)

Short name: 3'-5'_exonuclease_dom

Overlapping homologous superfamilies

Domain relationships


This domain is responsible for the 3'-5' exonuclease proofreading activity of Escherichia coli DNA polymerase I (polI) and other enzymes, it catalyses the hydrolysis of unpaired or mismatched nucleotides. This domain consists of the amino-terminal half of the Klenow fragment in E. coli polI it is also found in the Werner syndrome helicase (WRN), focus forming activity 1 protein (FFA-1) and ribonuclease D (RNase D) [PMID: 9697700].

Werner syndrome is a human genetic disorder causing premature aging; the WRN protein has helicase activity in the 3'-5' direction [PMID: 9288107, PMID: 9224595]. The FFA-1 protein is required for formation of a replication foci and also has helicase activity; it is a homologue of the WRN protein [PMID: 9697700]. RNase D is a 3'-5' exonuclease involved in tRNA processing. Also found in this family is the autoantigen PM/Scl thought to be involved in polymyositis-scleroderma overlap syndrome.

GO terms

Biological Process

GO:0006139 nucleobase-containing compound metabolic process

Molecular Function

GO:0008408 3'-5' exonuclease activity
GO:0003676 nucleic acid binding

Cellular Component

No terms assigned in this category.

Contributing signatures

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