Human IMPDH1 protein, His tag

The protein encoded by this gene acts as a homotetramer to regulate cell growth. The encoded protein is an enzyme that catalyzes the synthesis of xanthine monophosphate (XMP) from inosine-5-monophosphate (IMP). This is the rate-limiting step in the de novo synthesis of guanine nucleotides. Defects in this gene are a cause of retinitis pigmentosa type 1 (RP1). Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 28]