Muzyukina, Polina, Shkaruta, Anton, Guzmán, Noemí M., Andreani, Jessica, Borges, Adair L., Bondy-Denomy, Joseph, Maikova, Anna, Semenova, Ekaterina, Severinov, Konstantin, Soutourina, Olga
Identification of an anti-CRISPR protein that inhibits the CRISPR-Cas type I-B system in Clostridioides difficile
mSphere. 2023, 8(6). https://doi.org/10.1128/msphere.00401-23
URI: http://hdl.handle.net/10045/138968
DOI: 10.1128/msphere.00401-23
ISSN: 2379-5042
Abstract: 
CRISPR-Cas systems provide prokaryotic hosts with adaptive immunity against mobile genetic elements. Many bacteriophages encode anti-CRISPR (Acr) proteins that inhibit host defense. The identification of Acr proteins is challenging due to their small size and high sequence diversity, and only a limited number has been characterized to date. In this study, we report the discovery of a novel Acr protein, AcrIB2, encoded by the φCD38-2 Clostridioides difficile phage that efficiently inhibits interference by the type I-B CRISPR-Cas system of the host and likely acts as a DNA mimic. Most C. difficile strains contain two cas operons, one encoding a full set of interference and adaptation proteins and another encoding interference proteins only. Unexpectedly, we demonstrate that only the partial operon is required for interference and is subject to inhibition by AcrIB2.
Keywords:Clostridioides difficile, Type I-B CRISPR-Cas interference, Cas operons, Enteropathogen, Anti-CRISPR, DNA mimicry, Phage
American Society for Microbiology
info:eu-repo/semantics/article