Serine O-acetyltransferase () is an enzyme that catalyzes the chemical reaction
acetyl-CoA + L-serine CoA + O-acetyl-L-serine
The two substrates of this enzyme are L-serine and acetyl-CoA. Its products are O-acetyl-L-serine and CoA.
This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The systematic name of this enzyme class is acetyl-CoA:L-serine O-acetyltransferase. Other names in common use include SATase, L-serine acetyltransferase, serine acetyltransferase, and serine transacetylase. This enzyme participates in cysteine metabolism and sulfur metabolism.
Structural studies As of late 2007, 7 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , and .
N terminal protein domain
In molecular biology, the protein domain SATase is short for Serine acetyltransferase and refers to an enzyme that catalyses the conversion of L-serine to L-cysteine in Escherichia coli. Its role is to catalyse the activation of L-serine by acetyl-CoA. This entry refers to the N-terminus of the protein which has a sequence that is conserved in plants and bacteria.
Function The N-terminal domain of the protein Serine O-acetyltransferase catalyses the O-acetylation of the amino acid and has been characterised in Escherichia coli, Salmonella typhimurium. and Phaseolus vulgaris.
The enzyme acts together with cysteine synthase to convert serine into cysteine, a precursor to the essential amino acid, methionine. Serine acetyltransferase has been overexpressed in transgenic plants. These should contain more essential sulphur amino acids meaning a healthier diet for humans and animals.
Structure The amino-terminal alpha-helical domain particularly the amino acid residues His158 (histidine in position 158) and Asp143 (aspartic acid in position 143) form a catalytic triad with the substrate for acetyl transfer. There are eight alpha helices that form the N-terminal domain.
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