2ooa

crystal structure of the UBA domain from Cbl-b ubiquitin ligase

spinqualitylabelsall models 2ooa, resolution 1.56Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2ooa 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 1.56Å Ligands: MSE Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CBLB_HUMAN E3 ubiquitin-protein ligase which accepts ubiquitin from specific E2 ubiquitin-conjugating enzymes, and transfers it to substrates, generally promoting their degradation by the proteasome. Negatively regulates TCR (T-cell receptor), BCR (B-cell receptor) and FCER1 (high affinity immunoglobulin epsilon receptor) signal transduction pathways. In naive T-cells, inhibits VAV1 activation upon TCR engagement and imposes a requirement for CD28 costimulation for proliferation and IL-2 production. Also acts by promoting PIK3R1/p85 ubiquitination, which impairs its recruitment to the TCR and subsequent activation. In activated T-cells, inhibits PLCG1 activation and calcium mobilization upon restimulation and promotes anergy. In B-cells, acts by ubiquitinating SYK and promoting its proteasomal degradation. May also be involved in EGFR ubiquitination and internalization. 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 Cbl proteins are E3 ubiquitin ligases that are negative regulators of many receptor tyrosine kinases. Cbl-b and c-Cbl contain a ubiquitin-associated (UBA) domain, which is present in a variety of proteins involved in ubiquitin-mediated processes. Despite high sequence identity, Cbl UBA domains display remarkably different ubiquitin-binding properties. Here, we report the crystal structure of the UBA domain of Cbl-b in complex with ubiquitin at 1.9 A resolution. The structure reveals an atypical mechanism of ubiquitin recognition by the first helix of the UBA. Helices 2 and 3 of the UBA domain form a second binding surface, which mediates UBA dimerization in the crystal and in solution. Site-directed mutagenesis demonstrates that Cbl-b dimerization is regulated by ubiquitin binding and required for tyrosine phosphorylation of Cbl-b and ubiquitination of Cbl-b substrates. These studies demonstrate a role for ubiquitin in regulating biological activity by promoting protein dimerization. Structural basis for ubiquitin-mediated dimerization and activation of the ubiquitin protein ligase Cbl-b.,Peschard P, Kozlov G, Lin T, Mirza IA, Berghuis AM, Lipkowitz S, Park M, Gehring K Mol Cell. 2007 Aug 3;27(3):474-85. PMID:17679095 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ubiquitin protein ligase 3D structures

Proteopedia Page Contributors and Editors (what is this?)

OCA