Monday, December 26, 2022

473 - Bacteriophage Bunks in Bacterial Barriers

By Jancheva and Böttcher,
2021, JACS 143:8344-8351
CC BY 4.0

This episode: A bacteriophage that overcomes the bacterial  CRISPR/Cas immune system by interrupting the CRISPR DNA with its own genome!
Download Episode (6.8 MB, 10 minutes)

Show notes:
Microbe of the episode: Wenzhou mammarenavirus
Bacteria have many ways to resist being exploited by bacteriophage viruses, including the adaptable CRISPR/Cas system that uses a piece of viral nucleic acid sequence to target and destroy incoming phages. But phages also have many ways to evade and disrupt bacterial defenses.

In this study, a phage is discovered that inserts its own genome into the CRISPR/Cas sequence in the bacterial genome, disrupting the bacterial defenses. To escape the defenses while it is doing this insertion, it carries genes for previously-unknown anti-CRISPR proteins. But inserting and removing a viral sequence from the bacterial genome is not always a clean procedure.

Journal Paper:
Varble A, Campisi E, Euler CW, Maguin P, Kozlova A, Fyodorova J, Rostøl JT, Fischetti VA, Marraffini LA. 2021. Prophage integration into CRISPR loci enables evasion of antiviral immunity in Streptococcus pyogenes. 12. Nat Microbiol 6:1516–1525.

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