2jk9
From Proteopedia
The structure of splA-ryanodine receptor domain and SOCS box containing 1 in complex with a PAR-4 peptide
Structural highlights
Function[SPSB1_HUMAN] Probable substrate recognition component of a SCF-like ECS (Elongin BC-CUL2/5-SOCS-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins.[1] [PAWR_HUMAN] Pro-apoptopic protein capable of selectively inducing apoptosis in cancer cells, sensitizing the cells to diverse apoptotic stimuli and causing regression of tumors in animal models. Induces apoptosis in certain cancer cells by activation of the Fas prodeath pathway and coparallel inhibition of NF-kappa-B transcriptional activity. Inhibits the transcriptional activation and augments the transcriptional repression mediated by WT1. Down-regulates the anti-apoptotic protein BCL2 via its interaction with WT1. Seems also to be a transcriptional repressor by itself. May be directly involved in regulating the amyloid precursor protein (APP) cleavage activity of BACE1.[2] 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 mammalian SPRY domain- and SOCS box-containing proteins, SPSB1 to SPSB4, belong to the SOCS box family of E3 ubiquitin ligases. Substrate recognition sites for the SPRY domain are identified only for human Par-4 (ELNNNL) and for the Drosophila orthologue GUSTAVUS binding to the DEAD-box RNA helicase VASA (DINNNN). To further investigate this consensus motif, we determined the crystal structures of SPSB1, SPSB2, and SPSB4, as well as their binding modes and affinities for both Par-4 and VASA. Mutation of each of the three Asn residues in Par-4 abrogated binding to all three SPSB proteins, while changing EL to DI enhanced binding. By comparison to SPSB1 and SPSB4, the more divergent protein SPSB2 showed only weak binding to Par-4 and was hypersensitive to DI substitution. Par-4((59-77)) binding perturbed NMR resonances from a number of SPSB2 residues flanking the ELNNN binding site, including loop D, which binds the EL/DI sequence. Although interactions with the consensus peptide motif were conserved in all structures, flanking sites in SPSB2 were identified as sites of structural change. These structural changes limit high-affinity interactions for SPSB2 to aspartate-containing sequences, whereas SPSB1 and SPSB4 bind strongly to both Par-4 and VASA peptides. Structural basis for Par-4 recognition by the SPRY domain- and SOCS box-containing proteins SPSB1, SPSB2, and SPSB4.,Filippakopoulos P, Low A, Sharpe TD, Uppenberg J, Yao S, Kuang Z, Savitsky P, Lewis RS, Nicholson SE, Norton RS, Bullock AN J Mol Biol. 2010 Aug 20;401(3):389-402. Epub 2010 Jun 16. PMID:20561531[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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