Differences in folate-protein interactions result in differing inhibition of native rat liver and recombinant glycine N-methyltransferase by 5-methyltetrahydrofolate

► We crystallized rat liver glycine N-methyltransferase with folate inhibitors. ► We compared structures of these complexes with that formed by recombinant protein. ► Folates establish more hydrogen bonds with native liver protein. ► This explains more efficient inhibition of liver glycine N-methyltransferase.