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0Researchers have identified a vast repertoire of prokaryotic STAND NTPases that function as antiviral defense systems by recognizing conserved components of the phage proteome. Through systematic phylogenetic analysis and genetic screening, the study uncovered at least 90 distinct protein families capable of sensing various structural and replicative phage proteins, including the major capsid protein (MCP). A detailed investigation of the Avs7 family revealed that it forms an asymmetric tetrameric complex upon binding to the MCP, a process significantly enhanced by the repurposing of the host's elongation factor Tu (EF-Tu). This interaction triggers a large conformational change that relieves autoinhibition, activating a nuclease domain to provide robust immunity against infection. Ultimately, the findings establish that structure-based pattern recognition is a widespread and fundamental strategy used by bacteria and archaea to detect and neutralize viral threats.
References:
Lee H, Luengo-Woods S, Zhang J, et al. Diverse bacterial pattern recognition receptors sense the conserved phage proteome[J]. bioRxiv, 2026.
