5T83

Structure of a guanidine-I riboswitch from S. acidophilus

5T83 の概要

• エントリーDOI: 10.2210/pdb5t83/pdb
• 分子名称: RNA (95-MER), STRONTIUM ION, SPERMINE (FULLY PROTONATED FORM), ... (7 entities in total)
• 機能のキーワード: riboswitch, guanidine, s-turn, a-minor, rna
• 由来する生物種: Sulfobacillus acidophilus DSM 10332
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 32722.14

構造登録者

Reiss, C.W.,Xiong, Y.,Strobel, S.A. (登録日: 2016-09-06, 公開日: 2017-01-11, 最終更新日: 2024-03-06)

主引用文献

Reiss, C.W.,Xiong, Y.,Strobel, S.A.
Structural Basis for Ligand Binding to the Guanidine-I Riboswitch.
Structure, 25:195-202, 2017

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: 28017522
DOI: 10.1016/j.str.2016.11.020

実験手法

X-RAY DIFFRACTION (2.71 Å)