Inositol-hexakisphosphate kinase

Inositol-hexakisphosphate kinase (, ATP:1D-myo-inositol-hexakisphosphate phosphotransferase) is an enzyme with system name ATP:1D-myo-inositol-hexakisphosphate 5-phosphotransferase. This enzyme catalyses the following chemical reaction


 * (1) ATP + 1D-myo-inositol hexakisphosphate $$\rightleftharpoons$$ ADP + 1D-myo-inositol 5-diphosphate 1,2,3,4,6-pentakisphosphate
 * (2) ATP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate $$\rightleftharpoons$$ ADP + 1D-myo-inositol diphosphate tetrakisphosphate (isomeric configuration unknown)

Three mammalian isoforms are known to exist.