3-acetamido-4,5-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy- 6-[2-[(2R,3S,4R,5R)-5-(2,4-dioxopyrimidin-1-yl)- 3,4-dihydroxyoxolan-2-yl]-2-hydroxyethyl]-4,5-dihydroxyoxan- Tunicamycin is a mixture of homologous nucleoside antibiotics that inhibits the UDP-HexNAc: polyprenol-P HexNAc-1-P family of enzymes.

In eukaryotes, this includes the enzyme GlcNAc phosphotransferase (GPT), which catalyzes the transfer of N-acetylglucosamine-1-phosphate from UDP-N-acetylglucosamine to dolichol phosphate in the first step of glycoprotein synthesis.

Tunicamycin homologues have varying molecular weights owing to the variability in fatty acid side chain conjugates.

[4] TunA uses the starter unit uridine diphosphate-N-acetyl-glucosamine (UDP-GlcNAc) and catalyzes the dehydration of the 6’ hydroxyl group.

TunN is a nucleotide diphosphatase, and catalyzes the removal of pyrophosphate from UTP to form uridine monophosphate.