9u75

5hmC specific restriction endonuclease Escherichia coli E. coli O157:H7 PD-T4-3

spinqualitylabelsall models 9u75, resolution 2.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 9u75 is a 4 chain structure with sequence from Escherichia coli O157:H7. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.803Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A9Q7EI50_ECO57 Publication Abstract from PubMed The evolutionary arms race between bacteria and phages drives the development of bacterial antiviral defense systems and phage counter-defense strategies. Restriction-modification (RM) systems protect bacteria by methylating 'self' DNA and cleaving unmodified phage DNA. Phages like T-even coliphages evade RM systems by substituting cytosine with 5-hydroxymethyl cytosine (5hmC) or 5-glucosylated hmC (5ghmC). Here, we characterize ‌a single-component antiviral defense system featuring a GIY-YIG endonuclease domain. Biochemical and structural analyses demonstrate that this defense system is a type IV modification-dependent restriction endonuclease that specifically degrades 5hmC- or 5ghmC-modified DNA, and we accordingly name it CMoRE (Cytosine Modification ‌R‌estriction Endonuclease). The crystal structures reveal an N-terminal GIY-YIG nuclease domain and a C-terminal modification-sensing domain. Unique features, including a 'GIYxY-YIG' motif and an inhibitory negatively charged loop, distinguish CMoRE as an additional member of the GIY-YIG family. This system not only highlights the evolutionary interplay between phages and bacteria but also presents CMoRE as a potential tool for precise genomic detection of 5hmC in mammals, with implications for epigenetics research and disease diagnostics. A bacterial defense system targeting modified cytosine of phage genomic DNA.,Liu R, Tang D, Niu M, Lei S, Zong Z, Chen Q, Yu Y Nat Commun. 2026 Jan 22. doi: 10.1038/s41467-026-68792-8. PMID:41571690 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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