Protein of unknown function DUF123 (IPR002837)

Short name: DUF123

Overlapping homologous superfamilies


Family relationships



This family includes a group of functionally uncharacterized hypothetical proteins from archaea and their bacterial homologs. These proteins contain a putative GIY-YIG domain that shows sequence homology with bacterial UvrC DNA repair proteins. Meanwhile, all of them share a C-terminal extension with semi-conserved Cys and His residues, which suggests that the extended region may be a zinc-binding nucleic acid interaction domain. Although the majority of family members have a standalone GIY-YIG domain composition, some of them do have additional endonulcease III domain or sugar fermentation stimulation protein domain, both of which are N-terminally fused to the GIY-YIG domain. As a result, those proteins could perform some other role by cooperating with different domains, which remains to be determined in the future [PMID: 16646971].

In Methanocaldococcus jannaschii (Methanococcus jannaschii) it occurs with an endonuclease domain IPR003265.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.