7DRS

Structure of SspE_40224

7DRS の概要

• エントリーDOI: 10.2210/pdb7drs/pdb
• 分子名称: SspE protein (1 entity in total)
• 機能のキーワード: dnase, dna binding protein, gtpase, unknown function, hydrolase
• 由来する生物種: Streptomyces yokosukanensis
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 348589.41

構造登録者

Haiyan, G.,Jinchuan, Z.,Chen, S.,Wang, L.,Wu, G. (登録日: 2020-12-29, 公開日: 2022-06-29, 最終更新日: 2023-11-29)

主引用文献

Gao, H.,Gong, X.,Zhou, J.,Zhang, Y.,Duan, J.,Wei, Y.,Chen, L.,Deng, Z.,Wang, J.,Chen, S.,Wu, G.,Wang, L.
Nicking mechanism underlying the DNA phosphorothioate-sensing antiphage defense by SspE.
Nat Commun, 13:6773-6773, 2022

PubMed Abstract: DNA phosphorothioate (PT) modification, with a nonbridging phosphate oxygen substituted by sulfur, represents a widespread epigenetic marker in prokaryotes and provides protection against genetic parasites. In the PT-based defense system Ssp, SspABCD confers a single-stranded PT modification of host DNA in the 5'-CCA-3' motif and SspE impedes phage propagation. SspE relies on PT modification in host DNA to exert antiphage activity. Here, structural and biochemical analyses reveal that SspE is preferentially recruited to PT sites mediated by the joint action of its N-terminal domain (NTD) hydrophobic cavity and C-terminal domain (CTD) DNA binding region. PT recognition enlarges the GTP-binding pocket, thereby increasing GTP hydrolysis activity, which subsequently triggers a conformational switch of SspE from a closed to an open state. The closed-to-open transition promotes the dissociation of SspE from self PT-DNA and turns on the DNA nicking nuclease activity of CTD, enabling SspE to accomplish self-nonself discrimination and limit phage predation, even when only a small fraction of modifiable consensus sequences is PT-protected in a bacterial genome.

PubMed: 36351933
DOI: 10.1038/s41467-022-34505-0

実験手法

X-RAY DIFFRACTION (3.42 Å)