5vzw
From Proteopedia
(New page: ==TRIM23 RING domain in complex with UbcH5-Ub== <StructureSection load='5vzw' size='340' side='right' caption='5vzw, resolution 2.28Å' scene=''> == Structural hig...) |
m (Protected "5vzw" [edit=sysop:move=sysop]) |
Revision as of 09:05, 9 August 2017
proteopedia linkproteopedia linkTRIM23 RING domain in complex with UbcH5-Ub
Structural highlights
Function[UB2D2_HUMAN] Accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. In vitro catalyzes 'Lys-48'-linked polyubiquitination. Mediates the selective degradation of short-lived and abnormal proteins. Functions in the E6/E6-AP-induced ubiquitination of p53/TP53. Mediates ubiquitination of PEX5 and autoubiquitination of STUB1 and TRAF6. Involved in the signal-induced conjugation and subsequent degradation of NFKBIA, FBXW2-mediated GCM1 ubiquitination and degradation, MDM2-dependent degradation of p53/TP53 and the activation of MAVS in the mitochondria by DDX58/RIG-I in response to viral infection. Essential for viral activation of IRF3.[1] [2] [3] [4] [5] [6] [7] [8] [TRI23_HUMAN] Acts as an E3 ubiquitin-protein ligase. In the presence of the human cytomegalovirus (HCMV) protein UL144, participates in 'Lys-63'-linked auto-ubiquitination of TRAF6 resulting in the virally controlled activation of NF-kappa-B at early time of infection. The C-terminus can act as an allosteric activator of the cholera toxin catalytic subunit.[9] [UBB_HUMAN] 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, DNA-damage responses as well as in signaling processes leading to activation of the transcription factor NF-kappa-B. 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.[10] [11] Publication Abstract from PubMedTripartite motif (TRIM) proteins comprise a large family of RING-type ubiquitin E3 ligases that regulate important biological processes. An emerging general model is that TRIMs form elongated antiparallel coiled-coil dimers that prevent interaction of the two attendant RING domains. The RING domains themselves bind E2 conjugating enzymes as dimers, implying that an active TRIM ligase requires higher-order oligomerization of the basal coiled-coil dimers. Here, we report crystal structures of the TRIM23 RING domain in isolation and in complex with an E2-ubiquitin conjugate. Our results indicate that TRIM23 enzymatic activity requires RING dimerization, consistent with the general model of TRIM activation. Structure and catalytic activation of the TRIM23 RING E3 ubiquitin ligase.,Dawidziak DM, Sanchez JG, Wagner JM, Ganser-Pornillos BK, Pornillos O Proteins. 2017 Jul 6. doi: 10.1002/prot.25348. PMID:28681414[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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