Ubiquilin (IPR015496)

Short name: Ubiquilin

Overlapping homologous superfamilies


Family relationships


Ubiquitin [PMID: 1647207] is a protein of seventy six amino acid residues, found in all eukaryotic cells and whose sequence is extremely well conserved from protozoan to vertebrates. It is widely known as a post-translational tag used to signal a protein's hydrolytic destruction. Other functions for ubiquitin, depend on its differential internal isopeptide linkages. In addition, several ubiquitin-like proteins have been discovered from genome-sequencing efforts, other structural studies, and genetic screens. These new data show that proteins with the ubiquitin domain are adaptable, transposable genetic elements, which have been appended to other genes and utilised for many different cellular functions, depending on the ubiquitin-like protein's identity, subcellular location, and method of covalent attachment. The post-translational ligation of proteins to members of the ubiquitin superfamily can signal many different fates for the target protein [PMID: 12645912].

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.

Ubiquilin is a Ubiquitin-like (UBL) protein and has an N-terminal UBL domain and a C-terminal Ub-associated (UBA) domain in its structure.

Contributing signatures

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