The mechanism of bacterial defense system DdmDE fromLactobacillus casei DOI Creative Commons
Pingping Huang, P. S. Yan, Lijie Guo

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 9, 2024

Abstract Bacteria has developed a diverse array of defense mechanisms to protect against invasion by mobile genetic elements. Recent study identified bacterial module DdmDE system which encodes helicase-nuclease fusion protein DdmD and putative prokaryotic Argonaute-like DdmE, imposing fitness advantages the bacteria eliminating invasive plasmids. However, mechanistic basis how detects degrades plasmids is not fully understood. Here, studying from Lactobacillus casei (LcDdmDE), we found that LcDdmD able degrade ssDNA nick in presence Mn 2+ , it exhibits 5’-3’ DNA helicase activity length-dependent mechanism. Meanwhile, serves as sensor utilizes guide recognize target DNA. We determined cryo-EM structures dimer bound with fork DNA, guide/target DNA-bound LcDdmE, complex LcDdmDE-bubble intermediate state well active state. Together functional analysis, revealed working mechanism LcDdmDE system. In such scenario, guided ssDNA, LcDdmE recruits auto-inhibited loading onto target. Through substantial conformational changes, dissociates into monomer unwind duplex for plasmid degradation. Our provides structural insights DdmDE, presenting pAgo-directed degradation allosterically regulated helicase-nuclease.

Language: Английский

A prokaryotic Argonaute protein recruits a helicase-nuclease to degrade invading plasmids DOI
Dmitriy Ignatov,

Vivekanandan Shanmuganathan,

Emmanuelle Charpentier

et al.

Cell, Journal Year: 2024, Volume and Issue: 187(19), P. 5223 - 5225

Published: Sept. 1, 2024

Language: Английский

Citations

0
The mechanism of bacterial defense system DdmDE fromLactobacillus casei DOI Creative Commons
Pingping Huang, P. S. Yan, Lijie Guo

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 9, 2024

Abstract Bacteria has developed a diverse array of defense mechanisms to protect against invasion by mobile genetic elements. Recent study identified bacterial module DdmDE system which encodes helicase-nuclease fusion protein DdmD and putative prokaryotic Argonaute-like DdmE, imposing fitness advantages the bacteria eliminating invasive plasmids. However, mechanistic basis how detects degrades plasmids is not fully understood. Here, studying from Lactobacillus casei (LcDdmDE), we found that LcDdmD able degrade ssDNA nick in presence Mn 2+ , it exhibits 5’-3’ DNA helicase activity length-dependent mechanism. Meanwhile, serves as sensor utilizes guide recognize target DNA. We determined cryo-EM structures dimer bound with fork DNA, guide/target DNA-bound LcDdmE, complex LcDdmDE-bubble intermediate state well active state. Together functional analysis, revealed working mechanism LcDdmDE system. In such scenario, guided ssDNA, LcDdmE recruits auto-inhibited loading onto target. Through substantial conformational changes, dissociates into monomer unwind duplex for plasmid degradation. Our provides structural insights DdmDE, presenting pAgo-directed degradation allosterically regulated helicase-nuclease.

Language: Английский

Citations

0