protein tyrosine phosphatase-like domain of myotubularin related phosphoinositide phosphatases 3 and 4
This subgroup of enzymatically active phosphatase domains of myotubularins consists of MTMR3, also known as ZFYVE10, and MTMR4, also known as ZFYVE11, and related domains. Beside the phosphatase domain, they contain a C-terminal FYVE 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.
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