Homologous Superfamily

HIT-like superfamily (IPR036265)

Short name: HIT-like_sf

Overlapping entries


The histidine triad motif (HIT) is related to the sequence H-phi-H-phi-H-phi-phi (where phi is a hydrophobic amino acid). Proteins containing HIT domains form a superfamily of nucleotide hydrolases and transferases that act on the alpha-phosphate of ribonucleotides [PMID: 12119013]. HIT-containing proteins fall into three families:

  • Hint family of protein kinase-interacting proteins. These include adenosine 5'-monophosphoramide hydrolases (e.g. HIT-nucleotide-binding protein, or HINT) and diadenosine polyphosphate hydrolases (e.g. fragile HIT protein, or FINT). These HIT domains have a topology similar to that found in the N-terminal of protein kinases [PMID: 15904496].
  • GalT family. These include specific nucleoside monophosphate transferases (e.g. galactose-1-phosphate uridylyltransferase, diadenosine tetraphosphate phosphorylase, and adenylyl sulphate:phosphate adenylytransferase). These HIT domains are a duplication consisting of 2 HIT-like motifs. This family binds zinc and iron.
  • mRNA decapping enzyme family. These include enzymes such as DcpS and Dcp2. The HIT-domain is usually C-terminal in these proteins [PMID: 15273322].

Contributing signatures

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