Ubiquitin domain (IPR000626)

Short name: Ubiquitin_dom

Overlapping homologous superfamilies

Domain relationships


Ubiquitin is a protein of 76 amino acid residues, found in all eukaryotic cells and whose sequence is extremely well conserved from protozoan to vertebrates. Ubiquitin acts through its post-translational attachment (ubiquitinylation) to other proteins, where these modifications alter the function, location or trafficking of the protein, or targets it for destruction by the 26S proteasome [PMID: 15454246].

Ubiquitin is a globular protein, the last four C-terminal residues (Leu-Arg-Gly-Gly) extending from the compact structure to form a 'tail', important for its function. The latter is mediated by the covalent conjugation of ubiquitin to target proteins, by an isopeptide linkage between the C-terminal glycine and the epsilon amino group of lysine residues in the target proteins.

Ubiquitin is expressed as three different precursors: a polymeric head-to-tail concatemer of identical units (polyubiquitin), and two N-terminal ubiquitin moieties, UbL40 and UbS27, that are fused to the ribosomal polypeptides L40 and S27, respectively. Specific endopeptidases cleave these precursor molecules [PMID: 15571815] to release ubiquitin moieties that are identical in sequence and contribute to the ubiquitin pool [PMID: 16185873]. Some organisms express additional ubiquitin fusion proteins [PMID: 12729753]. Furthermore, there are several ubiquitin-like proteins derived from ubiquitin [PMID: 12826404].

This entry represents a domain characteristic of ubiquitin (Ub) and ubiquitin-like (Ubl) proteins such as SUMO [PMID: 17491593, PMID: 15479240] and Nedd8 [PMID: 9857030].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005515 protein binding

Cellular Component

No terms assigned in this category.

Contributing signatures

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