pfam18145: SAVED (This model is not part of the current CDD release)
SMODS-associated and fused to various effectors sensor domain
Predicted to function as a sensor domain, sensing nucleotides or nucleotide derivatives generated by SMODS and other nucleotide synthetase domains. This domain has been characterized in CD-NTase-associated protein 4 (Cap4), the founding member of a major family of downstream receptors that specifically respond to nucleotide second messenger signals in CBASS immunity, a bacterial system that provides immunity against bacteriophage. SAVED exhibits divergence in its nucleotide binding pocket which enables the recognition of a wide range of CD-NTase products such as bacterial second messengers with alternative ring size, nucleobase, and 3'-5' or 2'-5' phosphodiester linkages. The sensing of ligands by SAVED activates effectors that are essential for CBASS-mediated protection of bacteria from phage infection.
Jiyao W et al.(2023). "The conserved domain database in 2023.",