9vff

Solution structure of XPC binding domain of a hHR23B variant - H274N/H323Q

spinqualitylabelsall models 9vff Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 9vff is a 1 chain structure with sequence from Homo sapiens. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR, 10 models Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RD23B_HUMAN Multiubiquitin chain receptor involved in modulation of proteasomal degradation. Binds to polyubiquitin chains. Proposed to be capable to bind simultaneously to the 26S proteasome and to polyubiquitinated substrates and to deliver ubiquitinated proteins to the proteasome. May play a role in endoplasmic reticulum-associated degradation (ERAD) of misfolded glycoproteins by association with PNGase and delivering deglycosylated proteins to the proteasome. Involved in global genome nucleotide excision repair (GG-NER) by acting as component of the XPC complex. Cooperatively with CETN2 appears to stabilize XPC. May protect XPC from proteasomal degradation. The XPC complex is proposed to represent the first factor bound at the sites of DNA damage and together with other core recognition factors, XPA, RPA and the TFIIH complex, is part of the pre-incision (or initial recognition) complex. The XPC complex recognizes a wide spectrum of damaged DNA characterized by distortions of the DNA helix such as single-stranded loops, mismatched bubbles or single stranded overhangs. The orientation of XPC complex binding appears to be crucial for inducing a productive NER. XPC complex is proposed to recognize and to interact with unpaired bases on the undamaged DNA strand which is followed by recruitment of the TFIIH complex and subsequent scanning for lesions in the opposite strand in a 5'-to-3' direction by the NER machinery. Cyclobutane pyrimidine dimers (CPDs) which are formed upon UV-induced DNA damage esacpe detection by the XPC complex due to a low degree of structural perurbation. Instead they are detected by the UV-DDB complex which in turn recruits and cooperates with the XPC complex in the respective DNA repair. In vitro, the XPC:RAD23B dimer is sufficient to initiate NER; it preferentially binds to cisplatin and UV-damaged double-stranded DNA and also binds to a variety of chemically and structurally diverse DNA adducts. XPC:RAD23B contacts DNA both 5' and 3' of a cisplatin lesion with a preference for the 5' side. XPC:RAD23B induces a bend in DNA upon binding. XPC:RAD23B stimulates the activity of DNA glycosylases TDG and SMUG1. Publication Abstract from PubMed Increasing brain complexity is a major step in the evolution of species. Here, we show that, in the transition from amphibians to reptiles, the DNA repair protein RAD23B acquires a metalloadaptor function that allows it to serve as a central hub for both metabolism and protection of genomic integrity. More specifically, RAD23B gains an allosteric H274/H323 copper-binding site to enable the transfer of copper from the universal copper transporter 1 (CTR1) uptake protein to all known copper metallochaperone pathways, while simultaneously making its canonical functions in DNA repair copper dependent. This layer of nutrient regulation allows organisms to withstand elevated levels of potentially toxic copper while augmenting metabolism in cells with high energetic needs across both physiology and disease, including neurons in the locus coeruleus, a key brain structure that regulates sleep, and cancer cells. RAD23B acquires a copper metalloadaptor function in amphibian-to-reptile evolution to increase metabolism and regulate genomic integrity.,Xiao T, He D, Liu D, Jia S, Chen Q, Silverman D, Maitra N, Huang AY, Pezacki A, Nguyen TT, Rao G, Tillage R, Deng K, Weinshenker D, Britt RD, Kelly MJS, Dan Y, Chang CJ Mol Cell. 2025 Sep 18;85(18):3443-3459.e11. doi: 10.1016/j.molcel.2025.08.024. PMID:40972527 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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