7BTQ

EcoR124I-DNA in the Restriction-Alleviation State

7BTQ の概要

• エントリーDOI: 10.2210/pdb7btq/pdb
• EMDBエントリー: 30182
• 分子名称: Type I restriction enzyme EcoR124II M protein, DNA (64-MER), Type-1 restriction enzyme EcoR124II specificity protein, ... (5 entities in total)
• 機能のキーワード: cryoelectron microscopy, innate immune mechanism, complex, immune system
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 322119.14

構造登録者

Gao, Y.,Gao, P. (登録日: 2020-04-02, 公開日: 2020-05-27, 最終更新日: 2024-03-27)

主引用文献

Gao, Y.,Cao, D.,Zhu, J.,Feng, H.,Luo, X.,Liu, S.,Yan, X.X.,Zhang, X.,Gao, P.
Structural insights into assembly, operation and inhibition of a type I restriction-modification system.
Nat Microbiol, 5:1107-1118, 2020

PubMed Abstract: Type I restriction-modification (R-M) systems are widespread in prokaryotic genomes and provide robust protection against foreign DNA. They are multisubunit enzymes with methyltransferase, endonuclease and translocase activities. Despite extensive studies over the past five decades, little is known about the molecular mechanisms of these sophisticated machines. Here, we report the cryo-electron microscopy structures of the representative EcoR124I R-M system in different assemblies (RMS, RMS and MS) bound to target DNA and the phage and mobile genetic element-encoded anti-restriction proteins Ocr and ArdA. EcoR124I can precisely regulate different enzymatic activities by adopting distinct conformations. The marked conformational transitions of EcoR124I are dependent on the intrinsic flexibility at both the individual-subunit and assembled-complex levels. Moreover, Ocr and ArdA use a DNA-mimicry strategy to inhibit multiple activities, but do not block the conformational transitions of the complexes. These structural findings, complemented by mutational studies of key intermolecular contacts, provide insights into assembly, operation and inhibition mechanisms of type I R-M systems.

PubMed: 32483229
DOI: 10.1038/s41564-020-0731-z

実験手法

ELECTRON MICROSCOPY (4.54 Å)