6TFE
Crystal structure of the ADP-binding domain of the NAD+ riboswitch with N6-Methyl-adenosine-5'-triphosphate (m6ATP)
Summary for 6TFE
Entry DOI | 10.2210/pdb6tfe/pdb |
Descriptor | Chains: A, MAGNESIUM ION, BROMIDE ION, ... (6 entities in total) |
Functional Keywords | rna structure; riboswitch; x-ray crystallography, non-coding rna, rna |
Biological source | Candidatus Koribacter versatilis Ellin345 |
Total number of polymer chains | 1 |
Total formula weight | 17801.09 |
Authors | Huang, L.,Lilley, D.M.J. (deposition date: 2019-11-14, release date: 2020-09-23, Last modification date: 2024-05-15) |
Primary citation | Huang, L.,Wang, J.,Lilley, D.M.J. Structure and ligand binding of the ADP-binding domain of the NAD+ riboswitch. Rna, 26:878-887, 2020 Cited by PubMed Abstract: The A motif is the first known NAD-dependent riboswitch, comprising two similar tandem bulged stem-loop structures. We have determined the structure of the 5' domain 1 of the riboswitch. It has three coaxial helical segments, separated by an ACANCCCC bulge and by an internal loop, with a tertiary contact between them that includes two C:G base pairs. We have determined the structure with a number of ligands related to NADH, but in each case only the ADP moiety is observed. The adenosine adopts an conformation, forms multiple hydrogen bonds across the width of the sugar edge of the penultimate C:G base pair of the helix preceding the bulge, and the observed contacts have been confirmed by mutagenesis and calorimetry. Two divalent metal ions play a key structural role at the narrow neck of the bulge. One makes direct bonding contacts to the diphosphate moiety, locking it into position. Thus the nucleobase, ribose, and phosphate groups of the ADP moiety are all specifically recognized by the RNA. The NAD riboswitch is modular. Domain 1 is an ADP binding domain that may be ancient and could potentially be used in combination with other ligand binding motifs such as CoA. PubMed: 32295864DOI: 10.1261/rna.074898.120 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (2.3 Å) |
Structure validation
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