Protein Domain : Metallothionein, family 6, nematoda IPR000853

Type	Family
Description	Metallothioneins (MT) are small proteins that bind heavy metals, such as zinc, copper, cadmium, nickel, etc. They have a high content of cysteine residues that bind the metal ions through clusters of thiolate bonds [ , , ]. The metallothionein superfamily comprises all polypeptides that resemble equine renal metallothionein in several respects, e.g. low molecular weight; high metal content; amino acid composition with high Cys and low aromatic residue content; unique sequence with characteristic distribution of cysteines, and spectroscopic manifestations indicative of metal thiolate clusters. A MT family subsumes MTs that share particular sequence-specific features and are thought to be evolutionarily related. Fifteen MT families have been characterised, each family being identified by its number and its taxonomic range. Nematode (family 6) MTs are 62-74 residue proteins, containing 18 conserved cysteines and binding 6 cadmium ions. The protein also binds cations of several transition elements. The cysteine residues are arranged in C-X-C and X-C-C-X groups. In particular, the consensus pattern K-C-C-x(3)-C-C has been found to be diagnostic of family 6 metallothioneins. The protein is induced by cadmium, and is abundantly and exclusively expressed in the intestinal cells of larvae and adult animals [ ]. Subfamilies of this family, n1 and n2, hit the same entry. It is known that the identity between n1 and n2 is about 60% and n2 is longer than n1.
Short Name	Metalthion_nemt