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 1S80, 1SSM, 1SSQ, 1SST, 1T3D, 1Y7L, and 2ISQ.

N terminal protein domain

SATase N terminal domain

The structure of the enzyme serine acetyltransferase- apoenzyme (truncated)

Identifiers

Symbol

SATase_N

Available protein structures:
Pfam	structures / ECOD
PDB	RCSB PDB; PDBe; PDBj
PDBsum	structure summary

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 E. coli.^[1] More specifically, 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.^[2]

Importance of function

The N-terminal domain of the protein Serine acetyltransferase helps catalyse acetyl transfer. This particular enzyme catalyses serine into cysteine which is eventually converted to the essential amino acid methionine. Of particular interest to scientists, is the ability to harness the natural ability of the enzyme, Serine acetyltransferase, to create nutritionally essential amino acids and to exploit this ability through transgenic plants. These transgenic plants would contain more essential sulphur amino acids meaning a healthier diet for humans and animals.^[3]

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.^[4] There are eight alpha helices that form the N-terminal domain.^[4]

References

^ Denk D, Böck A (March 1987). "L-cysteine biosynthesis in Escherichia coli: nucleotide sequence and expression of the serine acetyltransferase (cysE) gene from the wild-type and a cysteine-excreting mutant". J. Gen. Microbiol. 133 (3): 515–25. doi:10.1099/00221287-133-3-515. PMID 3309158.
^ Saito K, Yokoyama H, Noji M, Murakoshi I (July 1995). "Molecular cloning and characterization of a plant serine acetyltransferase playing a regulatory role in cysteine biosynthesis from watermelon". J. Biol. Chem. 270 (27): 16321–6. doi:10.1074/jbc.270.27.16321. PMID 7608200.
^ Tabe L, Wirtz M, Molvig L, Droux M, Hell R (March 2010). "Overexpression of serine acetlytransferase produced large increases in O-acetylserine and free cysteine in developing seeds of a grain legume". J. Exp. Bot. 61 (3): 721–33. doi:10.1093/jxb/erp338. PMC 2814105. PMID 19939888.
^ ^a ^b Pye VE, Tingey AP, Robson RL, Moody PC (September 2004). "The structure and mechanism of serine acetyltransferase from Escherichia coli". J. Biol. Chem. 279 (39): 40729–36. doi:10.1074/jbc.M403751200. PMID 15231846.

Kredich NM, Tomkins GM (1966). "The enzymic synthesis of L-cysteine in Escherichia coli and Salmonella typhimurium". J. Biol. Chem. 241 (21): 4955–65. PMID 5332668.
Smith IK, Thompson JF (1971). "Purification and characterization of L-serine transacetylase and O-acetyl-L-serine sulfhydrylase from kidney bean seedlings (Phaseolus vulgaris)". Biochim. Biophys. Acta. 227 (2): 288–95. doi:10.1016/0005-2744(71)90061-1. PMID 5550822.

v t e Transferases: acyltransferases (EC 2.3)
2.3.1: other than amino-acyl groups	acetyltransferases: Acetyl-Coenzyme A acetyltransferase N-Acetylglutamate synthase Choline acetyltransferase Dihydrolipoyl transacetylase Acetyl-CoA C-acyltransferase Beta-galactoside transacetylase Chloramphenicol acetyltransferase N-acetyltransferase Serotonin N-acetyl transferase HGSNAT ARD1A Histone acetyltransferase P300/CBP NAT2 palmitoyltransferases: Carnitine O-palmitoyltransferase CPT1 CPT2 Serine C-palmitoyltransferase SPTLC1 SPTLC2 other: Acyltransferase like 2 Aminolevulinic acid synthase Beta-ketoacyl-ACP synthase Glyceronephosphate O-acyltransferase Lecithin—cholesterol acyltransferase Glycerol-3-phosphate O-acyltransferase 1-acylglycerol-3-phosphate O-acyltransferase 2-acylglycerol-3-phosphate O-acyltransferase ABHD5
2.3.2: Aminoacyltransferases	Gamma-glutamyl transpeptidase Peptidyl transferase Transglutaminase Tissue transglutaminase Keratinocyte transglutaminase Factor XIII
2.3.3: converted into alkyl on transfer	Citrate synthase Decylcitrate synthase Citrate (Re)-synthase Decylhomocitrate synthase 2-methylcitrate synthase 2-ethylmalate synthase 3-ethylmalate synthase ATP citrate lyase Malate synthase HMG-CoA synthase HMGCS2 2-hydroxyglutarate synthase 3-propylmalate synthase 2-isopropylmalate synthase Homocitrate synthase Sulfoacetaldehyde acetyltransferase

v t e Enzymes
Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Diffusion-limited enzyme Cofactor Enzyme catalysis
Regulation	Allosteric regulation Cooperativity Enzyme inhibitor Enzyme activator
Classification	EC number Enzyme superfamily Enzyme family List of enzymes
Kinetics	Enzyme kinetics Eadie–Hofstee diagram Hanes–Woolf plot Lineweaver–Burk plot Michaelis–Menten kinetics
Types	EC1 Oxidoreductases (list) EC2 Transferases (list) EC3 Hydrolases (list) EC4 Lyases (list) EC5 Isomerases (list) EC6 Ligases (list) EC7 Translocases (list)