MAP kinase phosphatase <p>The dual specificity phosphatases, also known as MAP Kinase Phosphatases(MKP), constitute a class of phosphatases that reverse the activation of MAP(mitogen activated protein) kinases by dephosphorylating critical tyrosineand threonine residues [<cite idref="PUB00011585"/>]. This regulation is mediated via interaction of aKinase Interaction Motif (KIM) with the common docking domain of the kinase- this motif is shared with a number of other protein families that interactwith MAP kinases: these include kinases (MEKs), phosphatases (PTP-SL) andtranscription factors (Elk1). MKPs also share an active site motif with theprotein tyrosine phosphatases (PTPs). Different MKPs exhibit specificitytowards different members of the MAP kinase family [<cite idref="PUB00011587"/>].</p><p>The structure of the MPK catalytic domain is similar to that of the PTPs - the fold exhibits a complex mixed alpha-/beta-architecture. Thecatalytic mechanism involves a general acid (Asp92 in 1VHR) and a catalyticcysteine (130 in 1VHR), which acts as a nucleophile.</p>