Oligoribonuclease (IPR022894)

Short name: Oligoribonuclease

Overlapping homologous superfamilies

Family relationships



Oligoribonuclease (Orn) is a DEDDh-type DnaQ-like 3'-5' exoribonuclease that is responsible for degrading small oligoribonucleotides to mononucleotides. It contains three conserved sequence motifs termed ExoI, ExoII and ExoIII, with a specific Hx(4)D conserved pattern at ExoIII. These motifs are clustered around the active site and contain four conserved acidic residues that serve as ligands for the two metal ions required for catalysis. Orn is essential for Escherichia coli survival [PMID: 17029243]. The human homolog, also called Sfn (small fragment nuclease), is able to hydrolyze short single-stranded RNA and DNA oligomers. It plays a role in cellular nucleotide recycling [PMID: 10851236, PMID: 16682444].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0000175 3'-5'-exoribonuclease activity

Cellular Component

No terms assigned in this category.

Contributing signatures

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