Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Jan;5(1):48-55.
doi: 10.1038/s41564-019-0612-5. Epub 2019 Dec 9.

A jumbo phage that forms a nucleus-like structure evades CRISPR-Cas DNA targeting but is vulnerable to type III RNA-based immunity

Lucia M Malone  1 , Suzanne L Warring  1 , Simon A Jackson  1   2 , Carolin Warnecke  1   3 , Paul P Gardner  2   4 , Laura F Gumy  5 , Peter C Fineran  6   7
Affiliations

A jumbo phage that forms a nucleus-like structure evades CRISPR-Cas DNA targeting but is vulnerable to type III RNA-based immunity

Lucia M Malone et al. Nat Microbiol. 2020 Jan.

Abstract

CRISPR-Cas systems provide bacteria with adaptive immunity against bacteriophages1. However, DNA modification2,3, the production of anti-CRISPR proteins4,5 and potentially other strategies enable phages to evade CRISPR-Cas. Here, we discovered a Serratia jumbo phage that evades type I CRISPR-Cas systems, but is sensitive to type III immunity. Jumbo phage infection resulted in a nucleus-like structure enclosed by a proteinaceous phage shell-a phenomenon only reported recently for distantly related Pseudomonas phages6,7. All three native CRISPR-Cas complexes in Serratia-type I-E, I-F and III-A-were spatially excluded from the phage nucleus and phage DNA was not targeted. However, the type III-A system still arrested jumbo phage infection by targeting phage RNA in the cytoplasm in a process requiring Cas7, Cas10 and an accessory nuclease. Type III, but not type I, systems frequently targeted nucleus-forming jumbo phages that were identified in global viral sequence datasets. The ability to recognize jumbo phage RNA and elicit immunity probably contributes to the presence of both RNA- and DNA-targeting CRISPR-Cas systems in many bacteria1,8. Together, our results support the model that jumbo phage nucleus-like compartments serve as a barrier to DNA-targeting, but not RNA-targeting, defences, and that this phenomenon is widespread among jumbo phages.

PubMed Disclaimer

Comment in

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Hille, F. et al. The biology of CRISPR-Cas: backward and forward. Cell 172, 1239–1259 (2018). - DOI
    1. Bryson, A. L. et al. Covalent modification of bacteriophage T4 DNA inhibits CRISPR-Cas9. mBio 6, e00648 (2015). - PubMed - PMC
    1. Vlot, M. et al. Bacteriophage DNA glucosylation impairs target DNA binding by type I and II but not by type V CRISPR–Cas effector complexes. Nucleic Acids Res. 46, 873–885 (2018). - PubMed
    1. Pawluk, A., Davidson, A. R. & Maxwell, K. L. Anti-CRISPR: discovery, mechanism and function. Nat. Rev. Microbiol. 16, 12–17 (2018). - PubMed - PMC
    1. Bondy-Denomy, J., Pawluk, A., Maxwell, K. L. & Davidson, A. R. Bacteriophage genes that inactivate the CRISPR/Cas bacterial immune system. Nature 493, 429–432 (2013). - PubMed

Publication types

MeSH terms

LinkOut - more resources