Insertion sequence transposition inactivates CRISPR-Cas immunity.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37474569.
- Also identified by DOI 10.1038/s41467-023-39964-7 and PMC identifier 10359306.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
CRISPR-Cas immunity systems safeguard prokaryotic genomes by inhibiting the invasion of mobile genetic elements. Here, we screened prokaryotic genomic sequences and identified multiple natural transpositions of insertion sequences (ISs) into cas genes, thus inactivating CRISPR-Cas defenses. We then generated an IS-trapping system, using Escherichia coli strains with various ISs and an inducible cas nuclease, to monitor IS insertions into cas genes following the induction of double-strand DNA breakage as a physiological host stress. We identified multiple events mediated by different ISs, especially IS1 and IS10, displaying substantial relaxed target specificity. IS transposition into cas was maintained in the presence of DNA repair machinery, and transposition into other host defense systems was also detected. Our findings highlight the potential of ISs to counter CRISPR activity, thus increasing bacterial susceptibility to foreign DNA invasion.
Medical subject headings
- DNA Transposable Elements
- CRISPR-Cas Systems