CRISPR-cas system evasion by virus

CRISPR/Cas (clustered Regularly Interspaced Short Palindromic Repeats /CRISP-associated proteins) system is a prokaryotic antiviral resistance mechanism which constitutes the only documented bacterial adaptive immune system. The adaptive feature of CRISPR-Cas immune system relies on its ability to integrate foreign short DNA sequences of invading molecules and integrate them in between the repetitive sequences of the CRISPR array in the form of spacers.
Following transcription and processing of these loci, the CRISPR antisens RNAs (crRNAs) guide the Cas proteins to complementary invading nucleic acid, which results in target interference.
The acquisition of new spacers allows the CRISPR-Cas immune system to rapidly adapt against new threats .

Bacterial viruses have developed strategies to circumvent this bacterial defense . Gene 35 from the Pseudomonas phage JBD30 encodes a protein able to suppress the CRISPR system, most probably after the crRNA biogenesis.

The vibrio cholera phage ICP1 instead encodes its own CRISPR/Cas system to counteract a phage inhibitory chromosomal island of the bacterial host .

Matching UniProtKB/Swiss-Prot entries

3 entries grouped by strain (browse by keywords)

2 entries

Pseudomonas phage D3112 (Bacteriophage D3112) reference strain

ACR31_BPD31 Anti-CRISPR protein 31 (ACR3112-31) (Gene product 31) (gp31)
ACR30_BPD31 Anti-CRISPR protein 30 (Gene product 30) (gp30)

1 entry

Enterobacteria phage T4 (Bacteriophage T4) reference strain

GSTA_BPT4 DNA alpha-glucosyltransferase (AGT) (Alpha-GT) (EC