6qts

Crystal structure of a mutant Arabidopsis WD40 domain in complex with a photoreceptor

spinqualitylabelsall models 6qts, resolution 1.11Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6qts is a 2 chain structure with sequence from Arabidopsis thaliana. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.11Å Ligands: ACE, CME, CSO, GOL, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function UVR8_ARATH UV-B specific signaling component that acts as UV-B photoreceptor and plays a key role in establishing UV-protective responses in plants. Upon UV-B irradiation, UVR8 undergoes an immediate switch from homodimer to monomer, accumulates in the nucleus, interacts with the photomorphogenic repressor COP1 and regulates the expression of the transcription factor HY5 by associating with chromatin (through histone H2B binding) in the HY5 promoter region. UVR8 is involved in controlling aspects of leaf growth and morphogenesis in response to UV-B, is required for normal progression of endocycle and has a regulatory role in stomatal differentiation. Is required for plant circadian clock response to photomorphogenic UV-B light, partly through the transcriptional activation of responsive clock genes. Promotes photosynthetic efficiency at elevated levels of UV-B. Plays a role in mediating the effects of UV-B radiation on pathogen resistance by controlling the expression of the sinapate biosynthetic pathway. The two tryptophans, Trp-285 and Trp-233, serve collectively as the UV-B chromophore. Publication Abstract from PubMed Plants sense different parts of the sun's light spectrum using distinct photoreceptors, which signal through the E3 ubiquitin ligase COP1. Here, we analyze why many COP1-interacting transcription factors and photoreceptors harbor sequence-divergent Val-Pro (VP) motifs that bind COP1 with different binding affinities. Crystal structures of the VP motifs of the UV-B photoreceptor UVR8 and the transcription factor HY5 in complex with COP1, quantitative binding assays, and reverse genetic experiments together suggest that UVR8 and HY5 compete for COP1. Photoactivation of UVR8 leads to high-affinity cooperative binding of its VP motif and its photosensing core to COP1, preventing COP1 binding to its substrate HY5. UVR8-VP motif chimeras suggest that UV-B signaling specificity resides in the UVR8 photoreceptor core. Different COP1-VP peptide motif complexes highlight sequence fingerprints required for COP1 targeting. The blue-light photoreceptors CRY1 and CRY2 also compete with transcription factors for COP1 binding using similar VP motifs. Thus, our work reveals that different photoreceptors and their signaling components compete for COP1 via a conserved mechanism to control different light signaling cascades. Plant photoreceptors and their signaling components compete for COP1 binding via VP peptide motifs.,Lau K, Podolec R, Chappuis R, Ulm R, Hothorn M EMBO J. 2019 Sep 16;38(18):e102140. doi: 10.15252/embj.2019102140. Epub 2019 Jul , 15. PMID:31304983 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ubiquitin protein ligase 3D structures

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