catalytic domain of receptor-type tyrosine-protein phosphatase T, repeat 1
Receptor-type tyrosine-protein phosphatase T (PTPRT), also known as receptor-type tyrosine-protein phosphatase rho (RPTP-rho or PTPrho), 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. PTPRT is highly expressed in the nervous system and it plays a critical role in regulation of synaptic formation and neuronal development. It dephosphorylates a specific tyrosine residue in syntaxin-binding protein 1, a key component of synaptic vesicle fusion machinery, and regulates its binding to syntaxin 1. PTPRT has been identified as a potential candidate gene for autism spectrum disorder (ASD) susceptibility. It 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