4 phytase

In enzymology, a 4-phytase (EC 3.1.3.26) is an enzyme that catalyzes the chemical reaction

myo-inositol hexakisphosphate + H₂O ⇌ 1D-myo-inositol 1,2,3,4,5-pentakisphosphate + phosphate

Thus, the two substrates of this enzyme are myo-inositol hexakisphosphate and H₂O, whereas its two products are 1D-myo-inositol 1,2,3,4,5-pentakisphosphate and phosphate.

This enzyme belongs to the family of hydrolases, specifically those acting on phosphoric monoester bonds. The systematic name of this enzyme class is myo-inositol-hexakisphosphate 6-phosphohydrolase. Other names in common use include 6-phytase (name based on 1L-numbering system and not 1D-numbering), phytase, and phytate 6-phosphatase. This enzyme participates in inositol phosphate metabolism.