catalytic domain of receptor-type tyrosine-protein phosphatase U, repeat 1
Receptor-type tyrosine-protein phosphatase U (PTPRU), also known as pancreatic carcinoma phosphatase 2 (PCP-2), belongs to the type IIb subfamily of receptor protein tyrosine phosphatases (RPTPs), which belong to the larger family of classical tyrosine-specific protein tyrosine phosphatases (PTPs). PTPs (EC 3.1.3.48) catalyze the dephosphorylation of phosphotyrosine peptides. PTPRU/PCP-2 is the most distant member of the type IIb subfamily and may have a distinct biological function other than cell-cell aggregation. It localizes to the adherens junctions and directly binds and dephosphorylates beta-catenin, and regulates the balance between signaling and adhesive beta-catenin. It plays an important role in the maintenance of epithelial integrity. PTPRU contains an extracellular region with an Meprin-A5 (neuropilin)-mu (MAM) domain, an immunoglobulin (Ig) domain, and four fibronectin type III (FN3) repeats, a transmembrane domain, and an intracellular segment with a juxtamembrane domain similar to the cytoplasmic domain of classical cadherins and two tandem PTP domains. This model represents the first (repeat 1) PTP domain.
Feature 1: catalytic site [active site], 2 residue positions
Conserved feature residue pattern:C R
Evidence:
Comment:the catalytic cysteine initiates a nucleophilic attack on the phosphate group of the substrate, forming a transient phosphoenzyme intermediate and releasing the substrate dephosphorylated; the transition state is stabilized by the arginine present in the catalytic pocket