Nicotinamide-N-Methyltransferase (NNMT)

Nicotinamide N-methyltransferase (EC 2.1.1.1) catalyzes the N-methylation of nicotinamide and other pyridines. Human liver NNMT activity has a bimodal frequency distribution, an observation that raises the possibility that this enzyme activity may be regulated by a genetic polymorphism. Such a polymorphism could have functional implications for individual differences in drug and xenobiotic toxicity.Transcription initiation for the NNMT gene occurred 105 to 109 bp 5-prime upstream from the cDNA translation initiation codon, as determined by both primer extension and 5-prime rapid amplification of cDNA ends. By fluorescence in situ hybridization, they mapped NNMT to 11q23.1.