A20 peptidase (IPR033478)

Short name: A20

Overlapping homologous superfamilies


Family relationships



The A20 peptidase (MEROPS identifier C64.003, also known as tumour necrosis factor alpha-induced protein 3, because the gene is induced by the cytokine tumour-necrosis factor alpha [PMID: 2406243]) is a bifunctional enzyme that can both ligate ubiquitin to a protein, and hydrolyse the isopeptide bond created. The C-terminal half of the protein contains seven novel C2/C2 zinc finger repeats [PMID: 2118515], which function as a ubiquitin ligase [PMID: 15258597]. The N-terminal half of the protein is the de-ubiquitinase [PMID: 15258597] specific for Lys48-linked diubiquitin and Lys63-linked ubiquitin chains [PMID: 23827681, PMID: 15258597]. A20 is a potent inhibitor of nuclear factor-kappa enhancer binding protein (NF-kappaB) signalling by polyubiquitinating the receptor-binding protein and targetting it for proteasomal degradation, but can also de-ubiquitinate the protein and rescue it from degradation [PMID: 15258597]. The complex interactions of A20 with NK-kappaB transcription factors has been reviwed by Abbasi et al [PMID: 26124703].

GO terms

Biological Process

GO:0016579 protein deubiquitination
GO:0016567 protein ubiquitination

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

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