This is a domain of unknown function found on the C-terminal of C7orf25 protein UPF0415. The C-terminal domain is homologous to the known PIN-like domains. The PIN-like domain is widespread among eukaryotes, including animals, plants, and fungi, but also present in some cyanobacteria, Deinococcus, and dsDNA viruses from the Mimiviridae family. The domain retains up to four potential catalytic residues, thus, depending on the protein is predicted to be an active or inactive nuclease and in a majority of the family members, the PIN-like domain is N-terminally fused with a potentially active PD-(D/E)XK-like domain Pfam:PF18474 [1].

1: Comprehensive classification of the PIN domain-like superfamily. Matelska D, Steczkiewicz K, Ginalski K; Nucleic Acids Res. 2017;45:6995-7020. PMID:28575517