Chromosomal Localization and Structure of the Human Type II IMP Dehydrogenase Gene (IMPDH2)

We determined the chromosomal localization and structure of the gene encoding human type II inosine 5′-monophosphate dehydrogenase (IMPDH, EC 1.1.1.205), an enzyme associated with cellular proliferation, malignant transformation, and differentiation. Using polymerase chain reaction (PCR) primers specific for type II IMPDH, we screened a panel of human-Chinese hamster cell somatic hybrids and a separate deletion panel of chromosome 3 hybrids and localized the gene to 3p21.2→p24.2. Two overlapping yeast artificial chromosome clones containing the full gene for type II IMPDH (IMPDH2) were isolated, and a physical map of 117 kb of human genomic DNA in this region of chromosome 3 was constructed. The gene for type II IMPDH was localized and oriented on this map and found to span no more than 12.5 kb.