Kiwa is a membrane-embedded defense supercomplex activated at phage attachment sites Journal Article


Authors: Zhang, Z.; Todeschini, T. C.; Wu, Y.; Kogay, R.; Naji, A.; Cardenas Rodriguez, J.; Mondi, R.; Kaganovich, D.; Taylor, D. W.; Bravo, J. P. K.; Teplova, M.; Amen, T.; Koonin, E. V.; Patel, D. J.; Nobrega, F. L.
Article Title: Kiwa is a membrane-embedded defense supercomplex activated at phage attachment sites
Abstract: Bacteria and archaea deploy diverse antiviral defense systems, many of which remain mechanistically uncharacterized. Here, we characterize Kiwa, a widespread two-component system composed of the transmembrane sensor KwaA and the DNA-binding effector KwaB. Cryogenic electron microscopy (cryo-EM) analysis reveals that KwaA and KwaB assemble into a large, membrane-associated supercomplex. Upon phage binding, KwaA senses infection at the membrane, leading to KwaB binding of ejected phage DNA and inhibition of replication and late transcription, without inducing host cell death. Although KwaB can bind DNA independently, its antiviral activity requires association with KwaA, suggesting spatial or conformational regulation. We show that the phage-encoded DNA-mimic protein Gam directly binds and inhibits KwaB but that co-expression with the Gam-targeted RecBCD system restores protection by Kiwa. Our findings support a model in which Kiwa coordinates membrane-associated detection of phage infection with downstream DNA binding by its effector, forming a spatially coordinated antiviral mechanism. © 2025 The Author(s)
Keywords: dna binding; phage defense; dna mimic; kiwa; late transcription; recbcd; transmembrane kwaab supercomplex
Journal Title: Cell
ISSN: 0092-8674
Publisher: Cell Press  
Publication status: Online ahead of print
Date Published: 2025-07-23
Online Publication Date: 2025-07-23
Language: English
DOI: 10.1016/j.cell.2025.07.002
PROVIDER: scopus
PUBMED: 40730155
PMCID: PMC12348683
DOI/URL:
Notes: Article -- MSK Cancer Center Support Grant (P30 CA008748) acknowledged in PDF -- MSK corresponding author is Dinshaw Patel -- Source: Scopus
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MSK Authors
  1. Zhigang Zhang
    431 Zhang
  2. Dinshaw J Patel
    479 Patel
  3. Marianna Teplova
    19 Teplova