HEPN (IPR007842)

Short name: HEPN

Domain relationships



The HEPN (higher eukaryotes and prokaryotes nucleotide-binding) domain is a region of 110 residues found in the C terminus of sacsin, a chaperonin implicated in an early-onset neurodegenerative disease in human, and in many bacterial and archeabacterial proteins. There are three classes of proteins with HEPN domain:

  • Single-domain HEPN proteins found in many bacteria.
  • Two-domain proteins with N-terminal nucleotidyltransferase (NT) and C- terminal HEPN domains. This N-terminal NT domain belongs to a large family of NTs, which includes several classes of enzymes that are responsible for some types of bacterial resistance to aminoglycosides. These enzymes deactivate various antibiotics by transferring a nucleotidyl group to the drug.
  • A multidomain sacsin protein in genomes of fish and mammals. The HEPN domain is located at the C terminus of the protein, directly after the DnaJ domain (see PDOC00553).
  • The crystal structure of the HEPN domain from the TM0613 protein of Thermotoga maritima indicates that it is structurally similar to the C-terminal all- alpha-helical domain of kanamycin nucleotidyltransferases (KNTases). It is composed of five alpha helices, three of which form an up- and-down helical bundle, with a pair of short helices on the side. The distant structural similarity suggests that the HEPN domain might be involved in nucleotide binding [PMID: 12765831].

    Contributing signatures

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