protein tyrosine phosphatase-like domain of myotubularin related phosphoinositide phosphatase 8
Myotubularin related phosphoinositide phosphatase 8 (MTMR8) is enzymatically active and contains a C-terminal coiled-coil domain and an N-terminal PH-GRAM domain. 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. MTMR8 forms a complex with catalytically inactive MTMR9 and preferentially dephosphorylates PtdIns(3)P; the MTMR8/R9 complex inhibits autophagy. In zebrafish, it cooperates with PI3K to regulate actin filament modeling and muscle development.
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
Jiyao W et al.(2023). "The conserved domain database in 2023.",