PTP domain of receptor-type tyrosine-protein phosphatase M, repeat 2
Receptor-type tyrosine-protein phosphatase M (PTPRM), also known as protein-tyrosine phosphatase mu (R-PTP-mu or PTPmu), 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. PTPRM/PTPmu is a homophilic cell adhesion molecule expressed in CNS neurons and glia. It is required for E-, N-, and R-cadherin-dependent neurite outgrowth. Loss of PTPmu contributes to tumor cell migration and dispersal of human glioblastomas. PTPRM 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 second (repeat 2) 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