Download MendeleyControl of bacterial immune signaling by a WYL domain transcription factor.
Blankenchip, C.L., Nguyen, J.V., Lau, R.K., Ye, Q., Gu, Y., Corbett, K.D.(2022) Nucleic Acids Res 50: 5239-5250
- PubMed: 35536256 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1093/nar/gkac343
- Primary Citation Related Structures:
7TB5, 7TB6 - PubMed Abstract:
Bacteria use diverse immune systems to defend themselves from ubiquitous viruses termed bacteriophages (phages). Many anti-phage systems function by abortive infection to kill a phage-infected cell, raising the question of how they are regulated to avoid cell killing outside the context of infection. Here, we identify a transcription factor associated with the widespread CBASS bacterial immune system, that we term CapW. CapW forms a homodimer and binds a palindromic DNA sequence in the CBASS promoter region. Two crystal structures of CapW suggest that the protein switches from an unliganded, DNA binding-competent state to a ligand-bound state unable to bind DNA. We show that CapW strongly represses CBASS gene expression in uninfected cells, and that phage infection causes increased CBASS expression in a CapW-dependent manner. Unexpectedly, this CapW-dependent increase in CBASS expression is not required for robust anti-phage activity, suggesting that CapW may mediate CBASS activation and cell death in response to a signal other than phage infection. Our results parallel concurrent reports on the structure and activity of BrxR, a transcription factor associated with the BREX anti-phage system, suggesting that CapW and BrxR are members of a family of universal defense signaling proteins.
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA, USA.
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