Structural highlights
Function
UBI4P_YEAST Ubiquitin exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, and DNA-damage responses. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling (By similarity).
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The ubiquitin-associated (UBA) domain is one of the most frequently occurring motifs that recognize ubiquitin tags. Dsk2p, a UBA-containing protein from Saccharomyces cerevisiae, is involved in the ubiquitin-proteasome proteolytic pathway and has been implicated in spindle pole duplication. Here we present the solution structure of the UBA domain of Dsk2p (Dsk2(UBA)) in complex with ubiquitin. The structure reveals that the UBA domain uses a mode of ubiquitin recognition that is similar to that of the CUE domain, another ubiquitin binding motif that shares low sequence homology but high structural similarity with UBA domains. These two domains, as well as the structurally unrelated ubiquitin binding motif UIM, provide a common, crucial recognition site for ubiquitin, comprising a hydrogen-bonding acceptor for the amide group of Gly-47, and a methyl group that packs against the hydrophobic pocket of ubiquitin formed by Leu-8, Ile-44, His-68, and Val-70.
Structure of the UBA domain of Dsk2p in complex with ubiquitin molecular determinants for ubiquitin recognition.,Ohno A, Jee J, Fujiwara K, Tenno T, Goda N, Tochio H, Kobayashi H, Hiroaki H, Shirakawa M Structure. 2005 Apr;13(4):521-32. PMID:15837191[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Ohno A, Jee J, Fujiwara K, Tenno T, Goda N, Tochio H, Kobayashi H, Hiroaki H, Shirakawa M. Structure of the UBA domain of Dsk2p in complex with ubiquitin molecular determinants for ubiquitin recognition. Structure. 2005 Apr;13(4):521-32. PMID:15837191 doi:10.1016/j.str.2005.01.011
