2vfj
From Proteopedia
STRUCTURE OF THE A20 OVARIAN TUMOUR (OTU) DOMAIN
Structural highlights
Function[TNAP3_HUMAN] Ubiquitin-editing enzyme that contains both ubiquitin ligase and deubiquitinase activities. Involved in immune and inflammatory responses signaled by cytokines, such as TNF-alpha and IL-1 beta, or pathogens via Toll-like receptors (TLRs) through terminating NF-kappa-B activity. Essential component of a ubiquitin-editing protein complex, comprising also RNF11, ITCH and TAX1BP1, that ensures the transient nature of inflammatory signaling pathways. In cooperation with TAX1BP1 promotes disassembly of E2-E3 ubiquitin protein ligase complexes in IL-1R and TNFR-1 pathways; affected are at least E3 ligases TRAF6, TRAF2 and BIRC2, and E2 ubiquitin-conjugating enzymes UBE2N and UBE2D3. In cooperation with TAX1BP1 promotes ubiquitination of UBE2N and proteasomal degradation of UBE2N and UBE2D3. Upon TNF stimulation, deubiquitinates 'Lys-63'-polyubiquitin chains on RIPK1 and catalyzes the formation of 'Lys-48'-polyubiquitin chains. This leads to RIPK1 proteasomal degradation and consequently termination of the TNF- or LPS-mediated activation of NF-kappa-B. Deubiquinates TRAF6 probably acting on 'Lys-63'-linked polyubiquitin. Upon T-cell receptor (TCR)-mediated T-cell activation, deubiquitinates 'Lys-63'-polyubiquitin chains on MALT1 thereby mediating disassociation of the CBM (CARD11:BCL10:MALT1) and IKK complexes and preventing sustained IKK activation. Deubiquinates NEMO/IKBKG; the function is facilitated by TNIP1 and leads to inhibition of NF-kappa-B activation. Upon stimulation by bacterial peptidoglycans, probably deubiquitinates RIPK2. Can also inhibit I-kappa-B-kinase (IKK) through a non-catalytic mechanism which involves polyubiquitin; polyubiquitin promotes association with IKBKG and prevents IKK MAP3K7-mediated phosphorylation. Targets TRAF2 for lysosomal degradation. In vitro able to deubiquitinate both 'Lys-48'- and 'Lys-63' polyubiquitin chains. Inhibitor of programmed cell death. Has a role in the function of the lymphoid system.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] 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 PubMedThe NF-kappaB (nuclear factor kappaB) regulator A20 antagonises IKK [IkappaB (inhibitor of kappaB) kinase] activation by modulating Lys63-linked polyubiquitination of cytokine-receptor-associated factors including TRAF2/6 (tumour-necrosis-factor-receptor-associated factor 2/6) and RIP1 (receptor-interacting protein 1). In the present paper we describe the crystal structure of the N-terminal OTU (ovarian tumour) deubiquitinase domain of A20, which differs from other deubiquitinases but shares the minimal catalytic core with otubain-2. Analysis of conserved surface regions allows prediction of ubiquitin-binding sites for the proximal and distal ubiquitin molecules. Structural and biochemical analysis suggests a novel architecture of the catalytic triad, which might be present in a subset of OTU domains including Cezanne and TRABID (TRAF-binding domain). Biochemical analysis shows a preference of the isolated A20 OTU domain for Lys48-linked tetraubiquitin in vitro suggesting that additional specificity factors might be required for the physiological function of A20 in cells. Structure of the A20 OTU domain and mechanistic insights into deubiquitination.,Komander D, Barford D Biochem J. 2008 Jan 1;409(1):77-85. PMID:17961127[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Human | Ubiquitinyl hydrolase 1 | Barford, D | Komander, D | Apoptosis | Cysteine protease | Cytokine signalling | Deubiquitinating enzyme | Dna-binding | Hydrolase | Lys63-linked | Metal-binding | Nf-kb | Nucleus | Otu | Ovarian tumour | Phosphorylation | Protease | Thiol protease | Ubiquitin | Ubl conjugation pathway | Zinc-finger
