6G87

Flavonoid-responsive Regulator FrrA

6G87 の概要

• エントリーDOI: 10.2210/pdb6g87/pdb
• 分子名称: TetR/AcrR family transcriptional regulator, 2-[N-CYCLOHEXYLAMINO]ETHANE SULFONIC ACID (2 entities in total)
• 機能のキーワード: flavonoids, repressor, tetr-family, transcription
• 由来する生物種: Bradyrhizobium diazoefficiens
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 96793.18

構造登録者

Werner, N.,Hoppen, J.,Palm, G.,Werten, S.,Goettfert, M.,Hinrichs, W. (登録日: 2018-04-07, 公開日: 2019-04-24, 最終更新日: 2024-11-13)

主引用文献

Werner, N.,Werten, S.,Hoppen, J.,Palm, G.J.,Gottfert, M.,Hinrichs, W.
The induction mechanism of the flavonoid-responsive regulator FrrA.
Febs J., 2021

PubMed Abstract: Bradyrhizobium diazoefficiens, a bacterial symbiont of soybean and other leguminous plants, enters a nodulation-promoting genetic programme in the presence of host-produced flavonoids and related signalling compounds. Here, we describe the crystal structure of an isoflavonoid-responsive regulator (FrrA) from Bradyrhizobium, as well as cocrystal structures with inducing and noninducing ligands (genistein and naringenin, respectively). The structures reveal a TetR-like fold whose DNA-binding domain is capable of adopting a range of orientations. A single molecule of either genistein or naringenin is asymmetrically bound in a central cavity of the FrrA homodimer, mainly via C-H contacts to the π-system of the ligands. Strikingly, however, the interaction does not provoke any conformational changes in the repressor. Both the flexible positioning of the DNA-binding domain and the absence of structural change upon ligand binding are corroborated by small-angle X-ray scattering (SAXS) experiments in solution. Together with a model of the promoter-bound state of FrrA our results suggest that inducers act as a wedge, preventing the DNA-binding domains from moving close enough together to interact with successive positions of the major groove of the palindromic operator.

PubMed: 34314575
DOI: 10.1111/febs.16141

実験手法

X-RAY DIFFRACTION (2.92 Å)