This is a highly divergent 3' exoribonuclease family. The proteins constitute a typical RNase fold, where the active site residues form a magnesium catalytic centre. The protein of the solved structure readily cleaves 3' overhangs in a time-dependent manner. It is similar to DEDD-type RNases and is an unusual ATP-binding protein that binds ATP and dATP. It forms a dimer in solution and both protomers in the asymmetric unit bind a magnesium ion through Asp-6 in SwissProt:P9WJ73. Proteins containing this domain also include 3'-5' exonuclease dexA from bacteriophage T4. It may play a role in the final step of host DNA degradation, by scavenging DNA into mononucleotides.
Jiyao W et al.(2023). "The conserved domain database in 2023.",