Cyclic dinucleotides (CDNs) play central roles in bacterial pathogenesis and innate immunity. The mammalian enzyme cGAS synthesizes a unique cyclic dinucleotide (cGAMP) containing a 2'-5' phosphodiester linkage essential for optimal immune stimulation, but the molecular basis for linkage specificity is unknown. Here, we show that the Vibrio cholerae pathogenicity factor DncV is a prokaryotic cGAS-like enzyme whose activity provides a mechanistic rationale for the unique ability of cGAS to produce 2'-5' cGAMP. Three high-resolution crystal structures show that DncV and human cGAS generate CDNs in sequential reactions that proceed in opposing directions. We explain 2' and 3' linkage specificity and test this model by reprogramming the human cGAS active site to produce 3'-5' cGAMP, leading to selective stimulation of alternative STING adaptor alleles in cells. These results demonstrate mechanistic homology between bacterial signaling and mammalian innate immunity and explain how active site configuration controls linkage chemistry for pathway-specific signaling.
This research output has an Altmetric Attention Score of 38. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 09 June 2026.
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#1,347,128
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#4,934
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#11,039
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Outputs of similar age from Cell
#64
of 156 outputs
Altmetric has tracked 33,779,198 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 96th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 19,368 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 63.1. This one has gotten more attention than average, scoring higher than 74% of its peers.
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We're also able to compare this research output to 156 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 58% of its contemporaries.
