Dual specificity phosphatases
dual specificity phosphatases
Dual-specificity phosphatase is a form of phosphatase that can act upon tyrosine or serine / threonine residues.   All [DUSPs] share a similar catalytic mechanism, by which a conserved cysteine residue forms a covalent intermediate with the phosphate group to be eliminated. The residues surrounding their calatytic core obey a rather strict consensus: His-Cys-x-x-x-x-x-Arg-Ser. The serine side chain and an additional conserved aspartate play a central role in the elimination of the Cys-linked intermediate, thus completing their enzymatic cycle. The main difference between tyrosine-specific phosphatases and dual-specificity phosphatases lies in the width of the latter enzymes' catalytic pocket: thus they can accommodate phosphorylated serine or threonine side chains as well as phosphorylated tyrosines.