7KD1

Apo structure of the THF riboswitch aptamer domain

7KD1 の概要

• エントリーDOI: 10.2210/pdb7kd1/pdb
• 分子名称: tetrahydrofolate riboswitch aptamer domain, SULFATE ION, MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: riboswitch, apo, gene regulation, rna
• 由来する生物種: Streptococcus mutans UA159
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 29065.58

構造登録者

Wilt, H.M.,Stagno, J.R.,Wang, Y.-X. (登録日: 2020-10-07, 公開日: 2021-03-03, 最終更新日: 2023-10-18)

主引用文献

Wilt, H.M.,Yu, P.,Tan, K.,Wang, Y.X.,Stagno, J.R.
Tying the knot in the tetrahydrofolate (THF) riboswitch: A molecular basis for gene regulation.
J.Struct.Biol., 213:107703-107703, 2021

PubMed Abstract: Effective gene regulation by the tetrahydrofolate riboswitch depends not only on ligand affinity but also on the kinetics of ligand association, which involves two cooperative binding sites. We have determined a 1.9-Å resolution crystal structure of the ligand-free THF riboswitch aptamer. The pseudoknot binding site 'unwinds' in the absence of ligand, whereby the adjacent helical domains (P1, P2, and P3) become disjointed, resulting in rotation and misalignment of the gene-regulatory P1 helix with respect to P3. In contrast, the second binding site at the three-way junction, which is the first to fold, is structurally conserved between apo and holo forms. This suggests a kinetic role for this site, in which binding of the first ligand molecule to the stably folded three-way junction promotes formation of the regulatory pseudoknot site and subsequent binding of the second molecule. As such, these findings provide a molecular basis for both conformational switching and kinetic control.

PubMed: 33571639
DOI: 10.1016/j.jsb.2021.107703

実験手法

X-RAY DIFFRACTION (1.9 Å)