An alpha+beta fold domain associated with restriction enzymes across prokaryotes and fused to JAB deubiquitinases, and chromatin proteins in a wide range of eukaryotes. The domain is predicted to function as a modified-DNA reader domain [1].

1: Adenine methylation in eukaryotes: Apprehending the complex evolutionary history and functional potential of an epigenetic modification. Iyer LM, Zhang D, Aravind L; Bioessays. 2016;38:27-40. PMID:26660621