| Type: | Domain | Name: | Ubiquitin E2 variant, N-terminal |
| Description: | The N-terminal ubiquitin E2 variant (UEV) domain is ~145 amino acid residues in length and shows significant sequence similarity to E2 ubiquitin ligases but is unable to catalyze ubiquitin transfer as it lacks the active site cysteine that forms the transient thioester bond with the C terminus of ubiquitin (Ub). Nevertheless, at least some UEVs have retained the ability to bind Ub, and appear to act either as cofactors in ubiquitylation reactions, or as ubiquitin sensors. UEV domains also frequently contain other protein recognition motifs, and may generally serve to couple protein and Ub binding functions to facilitate the formation of multiprotein complexes [, , , ]. The UEV domain consists of a twisted four-stranded antiparallel beta-sheet having a meander topology, with four alpha-helices packed against one face of the sheet. The UEV fold is generally similar to canonical E2 ligases in the hydrophobic core and 'active site' regions, but differs significantly at both its N- and C-termini [, ]. The UEV domain is found in the eukaryotic tumour susceptibility gene 101 protein (TSG101). Altered transcripts of this gene have been detected in sporadic breast cancers and many other Homo sapiensmalignancies. However, the involvement of this gene in neoplastic transformation and tumourigenesis is still elusive. TSG101 is required for normal cell function of embryonic and adult tissues but this gene is not a tumour suppressor for sporadic forms of breast cancer []. | Short Name: | UEV_N |
