2a25

Crystal structure of Siah1 SBD bound to the peptide EKPAAVVAPITTG from SIP

spinqualitylabelsall models 2a25, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2a25 is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.2Å Ligands: ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function SIAH1_HUMAN E3 ubiquitin-protein ligase that mediates ubiquitination and subsequent proteasomal degradation of target proteins. E3 ubiquitin ligases accept ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfers the ubiquitin to targeted substrates. Mediates E3 ubiquitin ligase activity either through direct binding to substrates or by functioning as the essential RING domain subunit of larger E3 complexes. Triggers the ubiquitin-mediated degradation of many substrates, including proteins involved in transcription regulation (ELL2, MYB, POU2AF1, PML and RBBP8), a cell surface receptor (DCC), the cell-surface receptor-type tyrosine kinase FLT3, the cytoplasmic signal transduction molecules (KLF10/TIEG1 and NUMB), an antiapoptotic protein (BAG1), a microtubule motor protein (KIF22), a protein involved in synaptic vesicle function in neurons (SYP), a structural protein (CTNNB1) and SNCAIP. Confers constitutive instability to HIPK2 through proteasomal degradation. It is thereby involved in many cellular processes such as apoptosis, tumor suppression, cell cycle, axon guidance, transcription regulation, spermatogenesis and TNF-alpha signaling. Has some overlapping function with SIAH2. Induces apoptosis in cooperation with PEG3. Upon nitric oxid (NO) generation that follows apoptotic stimulation, interacts with S-nitrosylated GAPDH, mediating the translocation of GAPDH to the nucleus. GAPDH acts as a stabilizer of SIAH1, facilitating the degradation of nuclear proteins. 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 Siah1 is the central component of a multiprotein E3 ubiquitin ligase complex that targets beta-catenin for destruction in response to p53 activation. The E3 complex comprises, in addition to Siah1, Siah-interacting protein (SIP), the adaptor protein Skp1, and the F-box protein Ebi. Here we show that SIP engages Siah1 by means of two elements, both of which are required for mediating beta-catenin destruction in cells. An N-terminal dimerization domain of SIP sits across the saddle-shaped upper surface of Siah1, with two extended legs packing against the sides of Siah1 by means of a consensus PXAXVXP motif that is common to a family of Siah-binding proteins. The C-terminal domain of SIP, which binds to Skp1, protrudes from the lower surface of Siah1, and we propose that this surface provides the scaffold for bringing substrate and the E2 enzyme into apposition in the functional complex. Structural analysis of Siah1-Siah-interacting protein interactions and insights into the assembly of an E3 ligase multiprotein complex.,Santelli E, Leone M, Li C, Fukushima T, Preece NE, Olson AJ, Ely KR, Reed JC, Pellecchia M, Liddington RC, Matsuzawa S J Biol Chem. 2005 Oct 7;280(40):34278-87. Epub 2005 Aug 4. PMID:16085652 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ubiquitin protein ligase 3D structures

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