PNMT
Description
The PNMT (phenylethanolamine N-methyltransferase) is a protein-coding gene located on chromosome 17.
PNMT is an enzyme primarily found in the adrenal medulla, where it converts norepinephrine to epinephrine. It is also expressed in small groups of neurons in the brain and certain cardiomyocytes. PNMT is a 30 kDa protein encoded by a gene on chromosome 17 with 4 exons. Structurally, it shares similarities with other methyltransferases, particularly glycine-N-methyl transferase (GNMT) and catechol-O-methyl transferase (COMT). Its folding lip suggests that PNMT evolved later than COMT but before other methyltransferases. The active site binds S-adenosyl-L-methionine (SAM) via pi stacking interactions with aromatic residues. There are 7 conserved aromatic residues in the active site across all known PNMT variants.
PNMT catalyzes the conversion of norepinephrine to epinephrine using S-adenosyl-L-methionine as a methyl donor. It can also methylate other substrates such as phenylethanolamine and octopamine. PNMT also methylates normetanephrine.
PNMT is also known as PENT, PNMTase.
