Serine O-acetyltransferase

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serine O-acetyltransferase
1ssq.jpg
Serine acetyltransferase hexamer, Haemophilus influenzae
Identifiers
EC no. 2.3.1.30
CAS no. 9023-16-9
Databases
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BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
Gene Ontology AmiGO / QuickGO
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PubMed articles
NCBI proteins

In enzymology, a serine O-acetyltransferase (EC 2.3.1.30) is an enzyme that catalyzes the chemical reaction

Contents

acetyl-CoA + L-serine CoA + O-acetyl-L-serine

Thus, the two substrates of this enzyme are acetyl-CoA and L-serine, whereas its two products are CoA and O-acetyl-L-serine.

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
PDB 1ssm EBI.jpg
The structure of the enzyme serine acetyltransferase- apoenzyme (truncated)
Identifiers
SymbolSATase_N
Pfam PF06426
InterPro IPR010493
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]

Related Research Articles

<span class="mw-page-title-main">Methionine</span> Sulfur-containing amino acid

Methionine is an essential amino acid in humans.

<span class="mw-page-title-main">Pyruvate dehydrogenase complex</span> Three-enzyme complex

Pyruvate dehydrogenase complex (PDC) is a complex of three enzymes that converts pyruvate into acetyl-CoA by a process called pyruvate decarboxylation. Acetyl-CoA may then be used in the citric acid cycle to carry out cellular respiration, and this complex links the glycolysis metabolic pathway to the citric acid cycle. Pyruvate decarboxylation is also known as the "pyruvate dehydrogenase reaction" because it also involves the oxidation of pyruvate.

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<span class="mw-page-title-main">Catalytic triad</span> Set of three coordinated amino acids

A catalytic triad is a set of three coordinated amino acids that can be found in the active site of some enzymes. Catalytic triads are most commonly found in hydrolase and transferase enzymes. An acid-base-nucleophile triad is a common motif for generating a nucleophilic residue for covalent catalysis. The residues form a charge-relay network to polarise and activate the nucleophile, which attacks the substrate, forming a covalent intermediate which is then hydrolysed to release the product and regenerate free enzyme. The nucleophile is most commonly a serine or cysteine amino acid, but occasionally threonine or even selenocysteine. The 3D structure of the enzyme brings together the triad residues in a precise orientation, even though they may be far apart in the sequence.

<span class="mw-page-title-main">Amino acid synthesis</span> The set of biochemical processes by which amino acids are produced

Amino acid biosynthesis is the set of biochemical processes by which the amino acids are produced. The substrates for these processes are various compounds in the organism's diet or growth media. Not all organisms are able to synthesize all amino acids. For example, humans can synthesize 11 of the 20 standard amino acids. These 11 are called the non-essential amino acids.

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Thiolases, also known as acetyl-coenzyme A acetyltransferases (ACAT), are enzymes which convert two units of acetyl-CoA to acetoacetyl CoA in the mevalonate pathway.

<span class="mw-page-title-main">Transsulfuration pathway</span>

The transsulfuration pathway is a metabolic pathway involving the interconversion of cysteine and homocysteine through the intermediate cystathionine. Two transsulfurylation pathways are known: the forward and the reverse.

<span class="mw-page-title-main">Homoserine dehydrogenase</span> Enzyme

In enzymology, a homoserine dehydrogenase (EC 1.1.1.3) is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">Histidinol dehydrogenase</span>

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<span class="mw-page-title-main">Aspartate-semialdehyde dehydrogenase</span> Amino-acid-synthesizing enzyme in fungi, plants and prokaryota

In enzymology, an aspartate-semialdehyde dehydrogenase is an enzyme that is very important in the biosynthesis of amino acids in prokaryotes, fungi, and some higher plants. It forms an early branch point in the metabolic pathway forming lysine, methionine, leucine and isoleucine from aspartate. This pathway also produces diaminopimelate which plays an essential role in bacterial cell wall formation. There is particular interest in ASADH as disabling this enzyme proves fatal to the organism giving rise to the possibility of a new class of antibiotics, fungicides, and herbicides aimed at inhibiting it.

<span class="mw-page-title-main">Diaminopimelate epimerase</span>

In enzymology, a diaminopimelate epimerase is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">UDP-glucose 4-epimerase</span> Class of enzymes

The enzyme UDP-glucose 4-epimerase, also known as UDP-galactose 4-epimerase or GALE, is a homodimeric epimerase found in bacterial, fungal, plant, and mammalian cells. This enzyme performs the final step in the Leloir pathway of galactose metabolism, catalyzing the reversible conversion of UDP-galactose to UDP-glucose. GALE tightly binds nicotinamide adenine dinucleotide (NAD+), a co-factor required for catalytic activity.

<span class="mw-page-title-main">Isocitrate lyase</span>

Isocitrate lyase, or ICL, is an enzyme in the glyoxylate cycle that catalyzes the cleavage of isocitrate to succinate and glyoxylate. Together with malate synthase, it bypasses the two decarboxylation steps of the tricarboxylic acid cycle and is used by bacteria, fungi, and plants.

<span class="mw-page-title-main">Aminodeoxychorismate synthase</span>

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

<span class="mw-page-title-main">Phosphoribosylaminoimidazolesuccinocarboxamide synthase</span> Class of enzymes

In molecular biology, the protein domain SAICAR synthase is an enzyme which catalyses a reaction to create SAICAR. In enzymology, this enzyme is also known as phosphoribosylaminoimidazolesuccinocarboxamide synthase. It is an enzyme that catalyzes the chemical reaction

In enzymology, a [acyl-carrier-protein] S-acetyltransferase is an enzyme that catalyzes the reversible chemical reaction

In enzymology, a maltose O-acetyltransferase is an enzyme that catalyzes the chemical reaction

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

<span class="mw-page-title-main">Cys/Met metabolism PLP-dependent enzyme family</span>

In molecular biology, the Cys/Met metabolism PLP-dependent enzyme family is a family of proteins including enzymes involved in cysteine and methionine metabolism which use PLP (pyridoxal-5'-phosphate) as a cofactor.

References

  1. 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.
  2. 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.
  3. 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.
  4. 1 2 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.