• O-acetyl -L-serine
  • (2S )-3- acetyloxy -2- aminopropanoic acid

White crystalline powder


Soluble in methanol

Template: Infobox chemical / molecular formula search available

The chemical compound O- acetylserine (OAS ) is a naturally occurring, non -proteinogenic amino acid. She plays in bacteria and plants as raw material for the synthesis of cysteine ​​and reduced as a sensor for the availability of sulfur a role.


The synthesis of O- acetylserine is catalyzed by serine acetyltransferases, wherein L-serine is acetylated with acetyl -coenzyme A as a cofactor to the hydroxy group. Be lyases by O - acetylserine ( thiol) O- acetylserine and hydrogen sulfide with elimination of acetate to cysteine ​​.

Signal character

With sulfur deficiency accumulates not to cysteine ​​unreacted O- acetylserine and then used in plants as a signal substance for those same sulfur deficiency. Subsequently, the expression of genes of the sulfur assimilation is increased. In particular O - acetylserine regulates its own formation, since it leads to dissociation of the serine acetyltransferase and O- acetylserine ( thiol) lyase produced cysteine ​​synthase complex. Since serine acetyltransferases are only active in the complex, thereby, the synthesis of O- acetylserine is braked.