IDI1 Background Information
IDI1 (isopentenyl-diphosphate delta isomerase 1), also known as IPP1 or IPPI1, is a 227 amino acid member of the IPP isomerase type I family and is involved in cholesterol biosynthesis. Localized to the peroxisome, IDI1 catalytically converts isopentenyl diphosphate (IPP) to its electrophilic isomer, dimethylallyl diphosphate (DMAPP). Specifically, IDI1 uses magnesium as a cofactor to catalyze the 1,3-allylic rearrangement of IPP, thus creating DMAPP, a substrate for subsequent reactions that synthesize farnesyl diphosphate and, ultimately, cholesterol. Defects in the gene encoding IDI1 may be associated with peroxisomal deficiency diseases, such as Zellweger syndrome, a congenital disorder caused by a reduction in the number of peroxisomes. Individuals affected with this disorder generally exhibit lack of muscle tone, an enlarged liver, mental retardation and, in some cases, death.
