8BFN

E. coli Wadjet JetABC dimer of dimers

8BFN の概要

• エントリーDOI: 10.2210/pdb8bfn/pdb
• EMDBエントリー: 15609 16020
• 分子名称: JetC, JetB, JetA, ... (4 entities in total)
• 機能のキーワード: smc complexes, bacterial immunity, defense system, dna loop extrusion, wadjet, jetabcd, dna cleavage, plasmid restriction, mksbefg, mobile genetic elements, horizontal gene transfer, eptabcd, mukbef, dna binding protein
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 10
• 化学式量合計: 738743.99

構造登録者

Roisne-Hamelin, F.,Beckert, B.,Myasnikov, A.,Li, Y.,Gruber, S. (登録日: 2022-10-26, 公開日: 2022-12-14, 最終更新日: 2024-07-24)

主引用文献

Liu, H.W.,Roisne-Hamelin, F.,Beckert, B.,Li, Y.,Myasnikov, A.,Gruber, S.
DNA-measuring Wadjet SMC ATPases restrict smaller circular plasmids by DNA cleavage.
Mol.Cell, 82:4727-4740.e6, 2022

PubMed Abstract: Structural maintenance of chromosome (SMC) complexes fold DNA by loop extrusion to support chromosome segregation and genome maintenance. Wadjet systems (JetABCD/MksBEFG/EptABCD) are derivative SMC complexes with roles in bacterial immunity against selfish DNA. Here, we show that JetABCD restricts circular plasmids with an upper size limit of about 100 kb, whereas a linear plasmid evades restriction. Purified JetABCD complexes cleave circular DNA molecules, regardless of the DNA helical topology; cleavage is DNA sequence nonspecific and depends on the SMC ATPase. A cryo-EM structure reveals a distinct JetABC dimer-of-dimers geometry, with the two SMC dimers facing in opposite direction-rather than the same as observed with MukBEF. We hypothesize that JetABCD is a DNA-shape-specific endonuclease and propose the "total extrusion model" for DNA cleavage exclusively when extrusion of an entire plasmid has been completed by a JetABCD complex. Total extrusion cannot be achieved on the larger chromosome, explaining how self-DNA may evade processing.

PubMed: 36525956
DOI: 10.1016/j.molcel.2022.11.015

実験手法

ELECTRON MICROSCOPY (3.52 Å)