3t6r
From Proteopedia
Structure of UHRF1 in complex with unmodified H3 N-terminal tail
Structural highlights
Disease[UHRF1_HUMAN] Note=Defects in UHRF1 may be a cause of cancers. Overexpressed in many different forms of human cancers, including bladder, breast, cervical, colorectal and prostate cancers, as well as pancreatic adenocarcinomas, rhabdomyosarcomas and gliomas. Plays an important role in the correlation of histone modification and gene silencing in cancer progression. Expression is associated with a poor prognosis in patients with various cancers, suggesting that it participates in cancer progression. Function[UHRF1_HUMAN] Multidomain protein that acts as a key epigenetic regulator by bridging DNA methylation and chromatin modification. Specifically recognizes and binds hemimethylated DNA at replication forks via its YDG domain and recruits DNMT1 methyltransferase to ensure faithful propagation of the DNA methylation patterns through DNA replication. In addition to its role in maintenance of DNA methylation, also plays a key role in chromatin modification: through its tudor-like regions and PHD-type zinc fingers, specifically recognizes and binds histone H3 trimethylated at 'Lys-9' (H3K9me3) and unmethylated at 'Arg-2' (H3R2me0), respectively, and recruits chromatin proteins. Enriched in pericentric heterochromatin where it recruits different chromatin modifiers required for this chromatin replication. Also localizes to euchromatic regions where it negatively regulates transcription possibly by impacting DNA methylation and histone modifications. Has E3 ubiquitin-protein ligase activity by mediating the ubiquitination of target proteins such as histone H3 and PML. It is still unclear how E3 ubiquitin-protein ligase activity is related to its role in chromatin in vivo. May be involved in DNA repair.[1] [2] [3] [4] [5] [6] [7] [8] [9] [H31T_HUMAN] Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. Publication Abstract from PubMedHuman multi-domain-containing protein UHRF1 has recently been extensively characterized as a key epigenetic regulator for maintaining DNA methylation patterns. UHRF1 SRA domain preferentially binds to hemimethylated CpG sites, and double Tudor domain has been implicated in recognizing H3K9me3 mark, but the role of the adjacent PHD finger remains unclear. Here, we report the high-resolution crystal structure of UHRF1 PHD finger in complex with N-terminal tail of histone H3. We found that the preceding zinc-Cys4 knuckle is indispensable for the PHD finger of UHRF1 to recognize the first four unmodified residues of histone H3 N-terminal tail. Quantitative binding studies indicated that UHRF1 PHD finger (including the preceding zinc-Cys4 knuckle) acts together with the adjacent double Tudor domain to specifically recognize the H3K9me3 mark. Combinatorial recognition of H3K9me3-containing histone H3 tail by UHRF1 PHD finger and double Tudor domain may play a role in establishing and maintaining histone H3K9 methylation patterns during the cell cycle. UHRF1 double tudor domain and the adjacent PHD finger act together to recognize K9me3-containing histone H3 tail.,Xie S, Jakoncic J, Qian C J Mol Biol. 2012 Jan 13;415(2):318-28. Epub 2011 Nov 12. PMID:22100450[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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