4aqu

Crystal structure of I-CreI complexed with its target methylated at position plus 2 (in the b strand) in the presence of calcium

spinqualitylabelsall models 4aqu, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4aqu is a 4 chain structure with sequence from Chlamydomonas reinhardtii and Synthetic construct. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.3Å Ligands: 5CM, CA, GOL Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function DNE1_CHLRE Endonuclease involved in group I intron homing. Recognizes and cleaves a 19-24 bp palindromic DNA site. Publication Abstract from PubMed In this study, we asked whether CpG methylation could influence the DNA binding affinity and activity of meganucleases used for genome engineering applications. A combination of biochemical and structural approaches enabled us to demonstrate that CpG methylation decreases I-CreI DNA binding affinity and inhibits its endonuclease activity in vitro. This inhibition depends on the position of the methylated cytosine within the DNA target and was almost total when it is located inside the central tetrabase. Crystal structures of I-CreI bound to methylated cognate target DNA suggested a molecular basis for such inhibition, although the precise mechanism still has to be specified. Finally, we demonstrated that the efficacy of engineered meganucleases can be diminished by CpG methylation of the targeted endogenous site, and we proposed a rational design of the meganuclease DNA binding domain to alleviate such an effect. We conclude that although activity and sequence specificity of engineered meganucleases are crucial parameters, target DNA epigenetic modifications need to be considered for successful gene editions. 5'-Cytosine-phosphoguanine (CpG) methylation impacts the activity of natural and engineered meganucleases.,Valton J, Daboussi F, Leduc S, Molina R, Redondo P, Macmaster R, Montoya G, Duchateau P J Biol Chem. 2012 Aug 31;287(36):30139-50. Epub 2012 Jun 27. PMID:22740697 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Endonuclease 3D structures

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