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4eoz

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Crystal structure of the SPOP BTB domain complexed with the Cul3 N-terminal domain

Structural highlights

4eoz is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[SPOP_HUMAN] Inhibits IPF1/PDX1 transactivation of established target promoters, such as insulin, may be by recruiting a repressor complex (By similarity). In complex with CUL3, involved in ubiquitination of BMI1, H2AFY and DAXX, and probably also in ubiquitination and proteasomal degradation of Gli2 or Gli3.^[1] ^[2] ^[3]

Publication Abstract from PubMed

The E3 ligases recruit substrate proteins for targeted ubiquitylation. Recent insights into the mechanisms of ubiquitylation demonstrate that E3 ligases can possess active regulatory properties beyond those of a simple assembly scaffold. Here, we describe the dimeric structure of the E3 ligase adaptor protein SPOP (speckle-type POZ protein) in complex with the N-terminal domain of Cul3 at 2.4 A resolution. We find that SPOP forms large oligomers that can form heteromeric species with the closely related paralog SPOPL. In combination, SPOP and SPOPL (SPOP-like) form a molecular rheostat that can fine-tune E3 ubiquitin ligase activity by affecting the oligomeric state of the E3 complex. We propose that adaptor protein self-assembly provides a graded level of regulation of the SPOP/Cul3 E3 ligase toward its multiple protein substrates.

Adaptor protein self-assembly drives the control of a cullin-RING ubiquitin ligase.,Errington WJ, Khan MQ, Bueler SA, Rubinstein JL, Chakrabartty A, Prive GG Structure. 2012 Jul 3;20(7):1141-53. Epub 2012 May 24. PMID:22632832^[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Furukawa M, He YJ, Borchers C, Xiong Y. Targeting of protein ubiquitination by BTB-Cullin 3-Roc1 ubiquitin ligases. Nat Cell Biol. 2003 Nov;5(11):1001-7. Epub 2003 Oct 5. PMID:14528312 doi:10.1038/ncb1056
↑ Hernandez-Munoz I, Lund AH, van der Stoop P, Boutsma E, Muijrers I, Verhoeven E, Nusinow DA, Panning B, Marahrens Y, van Lohuizen M. Stable X chromosome inactivation involves the PRC1 Polycomb complex and requires histone MACROH2A1 and the CULLIN3/SPOP ubiquitin E3 ligase. Proc Natl Acad Sci U S A. 2005 May 24;102(21):7635-40. Epub 2005 May 16. PMID:15897469 doi:0408918102
↑ Kwon JE, La M, Oh KH, Oh YM, Kim GR, Seol JH, Baek SH, Chiba T, Tanaka K, Bang OS, Joe CO, Chung CH. BTB domain-containing speckle-type POZ protein (SPOP) serves as an adaptor of Daxx for ubiquitination by Cul3-based ubiquitin ligase. J Biol Chem. 2006 May 5;281(18):12664-72. Epub 2006 Mar 8. PMID:16524876 doi:10.1074/jbc.M600204200
↑ Errington WJ, Khan MQ, Bueler SA, Rubinstein JL, Chakrabartty A, Prive GG. Adaptor protein self-assembly drives the control of a cullin-RING ubiquitin ligase. Structure. 2012 Jul 3;20(7):1141-53. Epub 2012 May 24. PMID:22632832 doi:http://dx.doi.org/10.1016/j.str.2012.04.009