5T83
Structure of a guanidine-I riboswitch from S. acidophilus
Summary for 5T83
| Entry DOI | 10.2210/pdb5t83/pdb |
| Descriptor | RNA (95-MER), STRONTIUM ION, SPERMINE (FULLY PROTONATED FORM), ... (7 entities in total) |
| Functional Keywords | riboswitch, guanidine, s-turn, a-minor, rna |
| Biological source | Sulfobacillus acidophilus DSM 10332 |
| Total number of polymer chains | 1 |
| Total formula weight | 32722.14 |
| Authors | Reiss, C.W.,Xiong, Y.,Strobel, S.A. (deposition date: 2016-09-06, release date: 2017-01-11, Last modification date: 2024-03-06) |
| Primary citation | Reiss, C.W.,Xiong, Y.,Strobel, S.A. Structural Basis for Ligand Binding to the Guanidine-I Riboswitch. Structure, 25:195-202, 2017 Cited by PubMed Abstract: The guanidine-I riboswitch is a conserved RNA element with approximately 2,000 known examples across four phyla of bacteria. It exists upstream of nitrogen metabolism and multidrug resistance transporter genes and alters expression through the specific recognition of a free guanidinium cation. Here we report the structure of a guanidine riboswitch aptamer from Sulfobacillus acidophilus at 2.7 Å resolution. Helices P1, P1a, P1b, and P2 form a coaxial stack that acts as a scaffold for ligand binding. A previously unidentified P3 helix docks into P1a to form the guanidinium binding pocket, which is completely enclosed. Every functional group of the ligand is recognized through hydrogen bonding to guanine bases and phosphate oxygens. Guanidinium binding is further stabilized through cation-π interactions with guanine bases. This allows the riboswitch to recognize guanidinium while excluding other bacterial metabolites with a guanidino group, including the amino acid arginine. PubMed: 28017522DOI: 10.1016/j.str.2016.11.020 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.71 Å) |
Structure validation
Download full validation report
