protein tyrosine phosphatase-like domain of myotubularin related phosphoinositide phosphatase 1
Myotubularin-related phosphoinositide phosphatase 1 (MTMR1) is enzymatically active and contains an N-terminal PH-GRAM domain, a C-terminal coiled-coiled domain and a PDZ binding site. MTMR1 is associated with myotonic dystrophy. In general, myotubularins are a unique subgroup of protein tyrosine phosphatases that use inositol phospholipids, rather than phosphoproteins, as substrates. They dephosphorylate the D-3 position of phosphatidylinositol 3-phosphate [PI(3)P] and phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2], generating phosphatidylinositol and phosphatidylinositol 5-phosphate [PI(5)P], respectively.
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