What is 1 Phosphatidylinositol 3 Kinase?

An enzyme that catalyzes the conversion of phosphatidylinositol to phosphatidylinositol 3-phosphate. This is the first committed step in the biosynthesis of phosphatidylinositol 3,4-bisphosphate and phosphatidylinositol 3,4,5-trisphosphate. This pathway is thought to play a critical role in DNA repair, V(D)J recombination and cell cycle checkpoints. EC 2.7.1.137.