4uw2 | pdb_00004uw2

Crystal structure of Csm1 in T.onnurineus

spinqualitylabelsall models 4uw2, resolution 2.63Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4uw2 is a 4 chain structure with sequence from Theon. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. NonStd Res: MSE Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed The CRISPR-Cas system is the RNA-guided immune defense mechanism in bacteria and archaea. Csm1 belongs to the Cas10 family, which is the common signature protein of the type III system. Csm1 is the largest subunit of the Csm interference complex in the type III-A subtype, which targets foreign DNA or RNA. Here, we report crystallographic and biochemical analyses of Thermococcus onnurineus Csm1, revealing a five-domain organization and single-stranded DNA (ssDNA)-specific nuclease activity associated with the N-terminal HD domain. This domain folds into permuted secondary structures in comparison with the HD domain of Cas3 and contains all the catalytically important residues. It exhibited both endo- and exonuclease activities in an Ni2+ or Mn2+-dependent manner. The narrow width of the active-site cleft appears to restrict the substrate specificity to ssDNA and thus to prevent Csm1 from cleaving double-stranded chromosomal DNA. These data suggest that Csm1 may function in DNA interference by the Csm effector complex. Crystal Structure of the Csm1 Subunit of the Csm Complex and Its Single-Stranded DNA-Specific Nuclease Activity.,Jung TY, An Y, Park KH, Lee MH, Oh BH, Woo E Structure. 2015 Mar 3. pii: S0969-2126(15)00045-3. doi:, 10.1016/j.str.2015.01.021. PMID:25773141 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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