Diphthine synthase

In enzymology, a diphthine synthase is an enzyme that catalyzes the chemical reaction


 * S-adenosyl-L-methionine + 2-(3-carboxy-3-aminopropyl)-L-histidine $$\rightleftharpoons$$ S-adenosyl-L-homocysteine + 2-[3-carboxy-3-(methylammonio)propyl]-L-histidine

Thus, the two substrates of this enzyme are S-adenosyl methionine and 2-(3-carboxy-3-aminopropyl)-L-histidine, whereas its two products are S-adenosylhomocysteine and 2-[3-carboxy-3-(methylammonio)propyl]-L-histidine.

This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:2-(3-carboxy-3-aminopropyl)-L-histidine methyltransferase. Other names in common use include S-adenosyl-L-methionine:elongation factor 2 methyltransferase, and diphthine methyltransferase.

Structural studies
As of late 2007, 84 structures have been solved for this class of enzymes, with PDB accession codes, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , and.