This family includes Anti-CBASS protein Acb1 which which counteracts or regulates the endogenous CBASS (cyclic oligonucleotide-based antiphage signalling system) antiviral defense system. It is a phosphodiesterase that enables metal-independent hydrolysis of the cyclic di- and trinucleotide CBASS signals [1].

1: Phage anti-CBASS and anti-Pycsar nucleases subvert bacterial immunity. Hobbs SJ, Wein T, Lu A, Morehouse BR, Schnabel J, Leavitt A, Yirmiya E, Sorek R, Kranzusch PJ; Nature. 2022;605:522-526. PMID:35395152