5lwj

Solution NMR structure of the GTP binding Class II RNA aptamer-ligand-complex containing a protonated adenine nucleotide with a highly shifted pKa.

spinqualitylabelsall models 5lwj Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5lwj is a 1 chain structure with sequence from Synthetic construct. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR Ligands: AP7, GTP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed RNA tertiary structure motifs are stabilized by a wide variety of hydrogen-bonding interactions. Protonated A and C nucleotides are normally not considered to be suitable building blocks for such motifs since their pKa values are far from physiological pH. Here, we report the NMR solution structure of an in vitro selected GTP-binding RNA aptamer bound to GTP with an intricate tertiary structure. It contains a novel kind of base quartet stabilized by a protonated A residue. Owing to its unique structural environment in the base quartet, the pKa value for the protonation of this A residue in the complex is shifted by more than 5 pH units compared to the pKa for A nucleotides in single-stranded RNA. This is the largest pKa shift for an A residue in structured nucleic acids reported so far, and similar in size to the largest pKa shifts observed for amino acid side chains in proteins. Both RNA pre-folding and ligand binding contribute to the pKa shift. A Stably Protonated Adenine Nucleotide with a Highly Shifted pKa Value Stabilizes the Tertiary Structure of a GTP-Binding RNA Aptamer.,Wolter AC, Weickhmann AK, Nasiri AH, Hantke K, Ohlenschlager O, Wunderlich CH, Kreutz C, Duchardt-Ferner E, Wohnert J Angew Chem Int Ed Engl. 2016 Nov 25. doi: 10.1002/anie.201609184. PMID:27885761 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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