InterPro domain: IPR039384

HINT (histidine triad nucleotide-binding protein) are related to the HIT family members that carry a motif HxHxH/Qxx (x, is a hydrophobic amino acid) [ 1 ]. On the basis of sequence, substrate specificity, structure, evolution and mechanism, HIT proteins are classified into three branches: the Hint branch, which consists of adenosine 5' -monophosphoramide hydrolases, the FHIT branch, that consists of diadenosine polyphosphate hydrolases, and the GalT branch consisting of specific nucloside monophosphate transferases [ 2 ]. HINT family includes members from all three forms of cellular life. Although the biochemical function has not been characterised for many of the members of this subgroup, the proteins from yeast have been shown to be involved in secretion, peroxisome formation and gene expression [ 3 , 4 ].

1. Structure-based analysis of catalysis and substrate definition in the HIT protein family. Science 278, 286-90
2. Hint, Fhit, and GalT: function, structure, evolution, and mechanism of three branches of the histidine triad superfamily of nucleotide hydrolases and transferases. Biochemistry 41, 9003-14
3. Adenosine monophosphoramidase activity of Hint and Hnt1 supports function of Kin28, Ccl1, and Tfb3. J. Biol. Chem. 277, 10852-60
4. Yeast cell cycle protein CDC48p shows full-length homology to the mammalian protein VCP and is a member of a protein family involved in secretion, peroxisome formation, and gene expression. J. Cell Biol. 114, 443-53