9ltj
Cryo-EM structure of DDB1-DDA1-DET1 complex
Structural highlights
FunctionDET1_HUMAN Component of the E3 ubiquitin ligase DCX DET1-COP1 complex, which is required for ubiquitination and subsequent degradation of target proteins. The complex is involved in JUN ubiquitination and degradation.[1] Publication Abstract from PubMedUbiquitin modifications regulate fundamental cellular activities by modulating protein stability and function. The ubiquitin ligase COP1, which is present across species from plants to humans, plays a crucial role in the ubiquitination of developmental transcription factors. While COP1 can function independently, it can also be incorporated into CULLIN4-RING ubiquitin ligase (CRL4) complexes through the DET1 adaptor protein. Despite its biological significance, the structural and functional mechanisms of COP1 and DET1-containing complexes remains poorly understood. Here we present the cryo-electron microscopy structures of human COP1 in complex with DDB1-DDA1-DET1 and Ube2e2, revealing an inactive stacked assembly state. Co-expression with COP1 substrates including c-Jun or ETS2 disrupts this configuration, inducing a conformational rearrangement into a distinct dimeric state that allows substrate access. Structural modelling identifies the spatial organization of COP1 WD40 domains where substrate recruits. DET1 serves as a structural scaffold, bridging COP1 and Ube2e2 to initiate potential ubiquitin addition on substrates, while DDB1 recruits the CULLIN4-RBX1 complex to facilitate Ube2d3-mediated ubiquitin chain elongation. These results reveal the dynamic interplay between the structural states of the CRL4(DET1-COP1) E3 ligase complex and its substrate specific activation mechanism, offering mechanistic insights into ubiquitination regulation and a basis for future studies on E3 ligase dynamics. Cryo-EM structure of the human COP1-DET1 ubiquitin ligase complex.,Wang S, Teng F, Stjepanovic G, Rao F, Su MY Nat Commun. 2026 Jan 15;17(1):543. doi: 10.1038/s41467-026-68375-7. PMID:41540009[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||