9DVU

CryoEM structure of RpaA bound to PkaiBC DNA and Syn7942 RNAP-SigA holoenzyme

9DVU の概要

• エントリーDOI: 10.2210/pdb9dvu/pdb
• EMDBエントリー: 47223
• 分子名称: Non-template DNA, MAGNESIUM ION, ZINC ION, ... (11 entities in total)
• 機能のキーワード: siga, rnap, tac, rpaa, response regulator, transcriptional regulator, dna binding protein, dna binding protein-dna complex, dna binding protein/dna
• 由来する生物種: Synechococcus elongatus; 詳細
• タンパク質・核酸の鎖数: 11
• 化学式量合計: 582784.99

構造登録者

Fang, M.,Gu, Y.,Matyszewski, M.,Leanca, M.,LiWang, A.,Yuzenkova, Y.,Corbett, K.D.,Golden, S.E. (登録日: 2024-10-08, 公開日: 2025-10-15, 最終更新日: 2026-05-27)

主引用文献

Fang, M.,Gu, Y.,Leanca, M.,Matyszewski, M.,LiWang, A.,Yuzenkova, Y.,Corbett, K.D.,Golden, S.S.
Mechanism and reconstitution of circadian transcription in cyanobacteria.
Nat.Struct.Mol.Biol., 33:275-281, 2026

PubMed Abstract: Circadian biological clocks evolved across kingdoms of life as an adaptation to predictable cycles of sunrise and sunset. In the cyanobacterium Synechococcus elongatus, a protein-based clock precisely controls when different genes are turned on and off during the 24-h day but the phasing mechanism remains unclear. Here we show the molecular basis of this regulation and reconstitute clock-controlled transcription in vitro using purified components. Biochemical and structural analyses revealed that the clock-regulated transcription factor RpaA can function as either an activator or a repressor of cyanobacterial RNA polymerase, depending on its binding position relative to core promoter elements. Leveraging the repressor mechanism, we developed a heterologous in vitro system driven by bacteriophage T7 RNA polymerase that sustains circadian transcription for multiple days. These findings explain how a single clock output generates opposite phases of gene expression and define the minimal components for circadian clock function, enabling synthetic or biotechnological applications.

PubMed: 41667880
DOI: 10.1038/s41594-025-01740-0

実験手法

ELECTRON MICROSCOPY (3.7 Å)