4xw1 | pdb_00004xw1

Crystal structure of (GCCU(G-LNA)CCUG)2 duplex

spinqualitylabelsall models 4xw1, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4xw1 is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.302Å Ligands: LCG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed RNA transcripts that include expanded CCUG repeats are associated with myotonic dystrophy type 2. Crystal structures of two CCUG-containing oligomers show that the RNA strands associate into slipped duplexes that contain noncanonical C-U pairs that have apparently undergone tautomeric transition or protonation resulting in an unusual Watson-Crick-like pairing. The overhanging ends of the duplexes interact forming U-U pairs, which also show tautomerism. Duplexes consisting of CCUG repeats are thermodynamically less stable than the trinucleotide repeats involved in the TRED genetic disorders, but introducing LNA residues increases their stability and raises the melting temperature of the studied oligomers by approximately 10 degrees C, allowing detailed crystallographic studies. Quantum mechanical calculations were performed to test the possibility of the tautomeric transitions or protonation within the noncanonical pairs. The results indicate that tautomeric or ionic shifts of nucleobases can manifest themselves in biological systems, supplementing the canonical "rules of engagement." Watson-Crick-like pairs in CCUG repeats: evidence for tautomeric shifts or protonation.,Rypniewski W, Banaszak K, Kulinski T, Kiliszek A RNA. 2016 Jan;22(1):22-31. doi: 10.1261/rna.052399.115. Epub 2015 Nov 5. PMID:26543073 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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