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Envelope stress is a trigger of CRISPR RNA‐mediated DNA silencing in Escherichia coli
Author(s) -
PerezRodriguez Ritsdeliz,
Haitjema Charles,
Huang Qingqiu,
Nam Ki Hyun,
Bernardis Sarah,
Ke Ailong,
DeLisa Matthew P.
Publication year - 2011
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2010.07482.x
Subject(s) - crispr , biology , plasmid , trans activating crrna , crispr interference , cas9 , rna , genetics , dna , gene silencing , gene
Summary A widespread feature in the genomes of most bacteria and archaea is an array of clustered, regularly interspaced short palindromic repeats (CRISPRs) that, together with a group of CRISPR‐associated (Cas) proteins, mediate immunity against invasive nucleic acids such as plasmids and viruses. Here, the CRISPR‐Cas system was activated in cells expressing a plasmid‐encoded protein that was targeted to the twin‐arginine translocation (Tat) pathway. Expression of this Tat substrate resulted in upregulation of the Cas enzymes and subsequent silencing of the encoding plasmid in a manner that required the BaeSR two‐component regulatory system, which is known to respond to extracytoplasmic stress. Furthermore, we confirm that the CasCDE enzymes form a stable ternary complex and appear to function as the catalytic core of the Cas system to process CRISPR RNA into its mature form. Taken together, our results indicate that the CRISPR‐Cas system targets DNA directly as part of a defence mechanism in bacteria that is overlapping with but not limited to phage infection.