4eoz
From Proteopedia
Crystal structure of the SPOP BTB domain complexed with the Cul3 N-terminal domain
Structural highlights
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 PubMedThe 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. See AlsoReferences
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