7EZY

anti-CRISPR-associated Aca2

7EZY の概要

• エントリーDOI: 10.2210/pdb7ezy/pdb
• 分子名称: anti-CRISPR-associated Aca2 (2 entities in total)
• 機能のキーワード: aca2, immune system, dna binding protein, autoregulator
• 由来する生物種: Oceanimonas smirnovii
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 28660.25

構造登録者

Lee, S.Y.,Park, H.H. (登録日: 2021-06-02, 公開日: 2022-01-12, 最終更新日: 2025-08-06)

主引用文献

Lee, S.Y.,Kim, G.E.,Park, H.H.
Molecular basis of transcriptional repression of anti-CRISPR by anti-CRISPR-associated 2.
Acta Crystallogr D Struct Biol, 78:59-68, 2022

PubMed Abstract: CRISPR-Cas systems are well known host defense mechanisms that are conserved in bacteria and archaea. To counteract CRISPR-Cas systems, phages and viruses have evolved to possess multiple anti-CRISPR (Acr) proteins that can inhibit the host CRISPR-Cas system via different strategies. The expression of acr genes is controlled by anti-CRISPR-associated (Aca) proteins that bind to an upstream promoter and regulate the expression of acr genes during transcription. Although the role of Aca as a transcriptional repressor has been demonstrated, the mechanism of action of Aca has not been determined. Here, the molecular mechanism underlying the Aca2-mediated transcriptional control of acr genes was elucidated by determining the crystal structure of Aca2 from Oceanimonas smirnovii at a high resolution of 1.92 Å. Aca2 forms a dimer in solution, and dimerization of Aca2 is critical for specific promoter binding. The promoter-binding strategy of dimeric Aca2 was also revealed by performing mutagenesis studies. The atomic structure of the Aca family shown in this study provides insights into the fine regulation of host defense and immune-escape mechanisms and also demonstrates the conserved working mechanism of the Aca family.

PubMed: 34981762
DOI: 10.1107/S2059798321011670

実験手法

X-RAY DIFFRACTION (1.92 Å)