3-dehydroquinate synthase

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3-dehydroquinate synthase
3-dehydroquinate synthase 3CLH.png
Ribbon representation of the Helicobacter pylori 3-dehydroquinate synthase. [1]
Identifiers
EC no. 4.2.3.4
CAS no. 37211-77-1
Databases
IntEnz IntEnz view
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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PMC articles
PubMed articles
NCBI proteins
3-dehydroquinate synthase
1nrx.jpg
3-Dehydroquinate synthase homodimer, Aspergillus nidulans
Identifiers
SymbolDHQ_synthase
Pfam PF01761
InterPro IPR002658
SCOP2 1dqs / SCOPe / SUPFAM
Available protein structures:
Pfam   structures / ECOD  
PDB RCSB PDB; PDBe; PDBj
PDBsum structure summary

The enzyme 3-dehydroquinate synthase (EC 4.2.3.4) catalyzes the chemical reaction

Contents

[[3-deoxy-D-arabino-hept-2-ulosonate 7-phosphate]] 3-dehydroquinate + phosphate

The protein uses NAD+ to catalyze the reaction. [2] [3] This reaction is part of the shikimate pathway which is involved in the biosynthesis of aromatic amino acids.

3-Dehydroquinate synthase belongs to the family of lyases, to be specific those carbon-oxygen lyases acting on phosphates. This enzyme participates in phenylalanine, tyrosine, and tryptophan biosynthesis. It employs one cofactor, cobalt (Co2+).

The reaction catalyzed by 3-dehydroquinate synthase Reaction catalyzed by 3-dehydroquinate synthase.svg
The reaction catalyzed by 3-dehydroquinate synthase

Background

The shikimate pathway is composed of seven steps, each catalyzed by an enzyme. The shikimate pathway is responsible for producing the precursors for aromatic amino acids, which are essential to our diets because we cannot synthesize them in our bodies. Only plants, bacteria, and microbial eukaryotes are capable of producing aromatic amino acids. The pathway ultimately converts phosphoenolpyruvate and 4-erythrose phosphate into chorismate, the precursor to aromatic amino acids. 3-Dehydroquinate synthase is the enzyme that catalyzes reaction in the second step of this pathway. This second step of the reaction eliminates a phosphate from 3-deoxy-D-arabino-heptulosonate 7-phosphate, which results in 3-dehydroquinate. 3-Dehydroquinate synthase is a monomeric enzyme, and has a molecular weight of 39,000. [4] 3-dehydroquinate synthase is activated by inorganic phosphate, and requires NAD+ for activity, although the reaction in total is neutral when catalyzed by an enzyme. [4]

Function

3-Dehydroquinate synthase utilizes a complex multi-step mechanism that includes alcohol oxidation, phosphate β-elimination, carbonyl reduction, ring opening, and intramolecular aldol condensation. [5] Dehydroquinate synthase requires NAD+ and a cobalt cofactor to catalyze the conversion of 3-deoxy-D-arabino-heptulosonate 7-phosphate into 3-dehydroquinate. Dehydroquinate synthase is of particular interest because of its complicated activity relative to its small size. [5] In most bacteria, this enzyme has only one function. However, in fungi and protists, it is part of the pentafunctional AROM complex that comprises steps two, three, four, five and six of the shikimate pathway. Together with 3-dehydroquinate dehydratase, 3-dehydroquinate synthase forms the core of this complex. [6]

Applications

3-Dehydroquinate synthase catalyzes the second step in the shikimate pathway, which is essential for the production of aromatic amino acids in bacteria, plants, and fungi, but not mammals. This makes it an ideal target for new antimicrobial agents, anti-parasitic agents, and herbicides. [1] Other enzymes in the shikimate pathway have already been targeted and put to use as herbicides.

This cartoon representation of 3-dehydroquinate synthase shows the arrangement of the secondary structure of the protein Cartoon Representation of 3-dehydroquinate synthase.png
This cartoon representation of 3-dehydroquinate synthase shows the arrangement of the secondary structure of the protein
3-dehydroquinate synthase interacting with its substrates NAD , carbaphosphonate, and Zn , which are shown as spheres in this representation 3-dehydroquinate synthase and its substrates.png
3-dehydroquinate synthase interacting with its substrates NAD , carbaphosphonate, and Zn , which are shown as spheres in this representation
This representation of 3-dehydroquinate synthase shows the surface of the enzyme, as well as the active site, which can be seen in the middle. Surface representation of 3-dehydroquinate synthase.png
This representation of 3-dehydroquinate synthase shows the surface of the enzyme, as well as the active site, which can be seen in the middle.

Nomenclature

The systematic name of this enzyme class is 3-deoxy-D-arabino-hept-2-ulosonate-7-phosphate phosphate-lyase (cyclizing; 3-dehydroquinate-forming). Other names in common use include 5-dehydroquinate synthase, 5-dehydroquinic acid synthetase, dehydroquinate synthase, 3-dehydroquinate synthetase, 3-deoxy-arabino-heptulosonate-7-phosphate phosphate-lyase, (cyclizing), and 3-deoxy-arabino-heptulonate-7-phosphate phosphate-lyase (cyclizing).

Related Research Articles

In molecular biology, biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism.

Shikimic acid, more commonly known as its anionic form shikimate, is a cyclohexene, a cyclitol and a cyclohexanecarboxylic acid. It is an important biochemical metabolite in plants and microorganisms. Its name comes from the Japanese flower shikimi, from which it was first isolated in 1885 by Johan Fredrik Eykman. The elucidation of its structure was made nearly 50 years later.

<span class="mw-page-title-main">Chorismic acid</span> Chemical compound

Chorismic acid, more commonly known as its anionic form chorismate, is an important biochemical intermediate in plants and microorganisms. It is a precursor for:

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

Amino acid synthesis 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).

<span class="mw-page-title-main">Erythrose 4-phosphate</span> Chemical compound

Erythrose 4-phosphate is a phosphate of the simple sugar erythrose. It is an intermediate in the pentose phosphate pathway and the Calvin cycle.

<span class="mw-page-title-main">Shikimate dehydrogenase</span> Enzyme involved in amino acid biosynthesis

In enzymology, a shikimate dehydrogenase (EC 1.1.1.25) is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">Phosphoribosylanthranilate isomerase</span> Enzyme involved in tryptophan synthesis

In enzymology, a phosphoribosylanthranilate isomerase (PRAI) is an enzyme that catalyzes the third step of the synthesis of the amino acid tryptophan.

<span class="mw-page-title-main">Cystathionine beta-lyase</span> Enzyme

Cystathionine beta-lyase, also commonly referred to as CBL or β-cystathionase, is an enzyme that primarily catalyzes the following α,β-elimination reaction

<span class="mw-page-title-main">3-dehydroquinate dehydratase</span> Class of enzymes

The enzyme 3-dehydroquinate dehydratase (EC 4.2.1.10) catalyzes the chemical reaction

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

The enzyme chorismate synthase catalyzes the chemical reaction

<span class="mw-page-title-main">Shikimate kinase</span> Class of enzymes

Shikimate kinase (EC 2.7.1.71) is an enzyme that catalyzes the ATP-dependent phosphorylation of shikimate to form shikimate 3-phosphate. This reaction is the fifth step of the shikimate pathway, which is used by plants and bacteria to synthesize the common precursor of aromatic amino acids and secondary metabolites. The systematic name of this enzyme class is ATP:shikimate 3-phosphotransferase. Other names in common use include shikimate kinase (phosphorylating), and shikimate kinase II.

The Aminoshikimate pathway is a biochemical pathway present in some plants, which has been studied by biologists, biochemists and especially those interested in manufacture of novel antibiotic drugs. The pathway is a novel variation of the shikimate pathway. The aminoshikimate pathway was first discovered and studied in the rifamycin B producer Amycolatopsis mediterranei. Its end product, 3-amino-5-hydroxybenzoate, serves as an initiator for polyketide synthases in the biosynthesis of ansamycins.

<span class="mw-page-title-main">Shikimate pathway</span> Biosynthetic Pathway

The shikimate pathway is a seven-step metabolic pathway used by bacteria, archaea, fungi, algae, some protozoans, and plants for the biosynthesis of folates and aromatic amino acids. This pathway is not found in mammals.

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

3-Deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) synthase is the first enzyme in a series of metabolic reactions known as the shikimate pathway, which is responsible for the biosynthesis of the amino acids phenylalanine, tyrosine, and tryptophan. Since it is the first enzyme in the shikimate pathway, it controls the amount of carbon entering the pathway. Enzyme inhibition is the primary method of regulating the amount of carbon entering the pathway. Forms of this enzyme differ between organisms, but can be considered DAHP synthase based upon the reaction that is catalyzed by this enzyme.

<span class="mw-page-title-main">EPSP synthase</span> Enzyme produced by plants and microorganisms

5-enolpyruvylshikimate-3-phosphate (EPSP) synthase is an enzyme produced by plants and microorganisms. EPSPS catalyzes the chemical reaction:

3-Deoxy-<small>D</small>-<i>arabino</i>-heptulosonic acid 7-phosphate Chemical compound

3-Deoxy-D-arabino-heptulosonic acid 7-phosphate (DAHP) is a 7-carbon ulosonic acid. This compound is found in the shikimic acid biosynthesis pathway and is an intermediate in the production of aromatic amino acids.

3-dehydroquinate synthase II (EC 1.4.1.24, DHQ synthase II, MJ1249 (gene), aroB' (gene)) is an enzyme with systematic name 2-amino-3,7-dideoxy-D-threo-hept-6-ulosonate:NAD+ oxidoreductase (deaminating). This enzyme catalyses the following chemical reaction

6-deoxy-5-ketofructose 1-phosphate synthase is an enzyme with systematic name 2-oxopropanal:D-fructose 1,6-bisphosphate glycerone-phosphotransferase. This enzyme catalyses the following chemical reaction

2-amino-3,7-dideoxy-D-threo-hept-6-ulosonate synthase is an enzyme with systematic name L-aspartate 4-semialdehyde:1-deoxy-D-threo-hexo-2,5-diulose 6-phosphate methylglyoxaltransferase. This enzyme catalyses the following chemical reaction

2-deoxy-scyllo-Inosose synthase is an enzyme with systematic name D-glucose-6-phosphate phosphate-lyase (2-deoxy-scyllo-inosose-forming). This enzyme catalyses the following chemical reaction

References

  1. 1 2 PDB: 3CLH ; Liu JS, Cheng WC, Wang HJ, Chen YC, Wang WC (August 2008). "Structure-based inhibitor discovery of Helicobacter pylori dehydroquinate synthase". Biochemical and Biophysical Research Communications. 373 (1): 1–7. doi:10.1016/j.bbrc.2008.05.070. PMID   18503755.; rendered with MacPyMOL
  2. Hawkins AR, Lamb HK (August 1995). "The molecular biology of multidomain proteins. Selected examples". European Journal of Biochemistry. 232 (1): 7–18. doi:10.1111/j.1432-1033.1995.tb20775.x. PMID   7556173.
  3. Barten R, Meyer TF (April 1998). "Cloning and characterisation of the Neisseria gonorrhoeae aroB gene". Molecular & General Genetics. 258 (1–2): 34–44. doi:10.1007/s004380050704. PMID   9613570. S2CID   26380973.
  4. 1 2 Herrmann KM, Weaver LM (June 1999). "The Shikimate Pathway". Annual Review of Plant Physiology and Plant Molecular Biology. 50: 473–503. doi:10.1146/annurev.arplant.50.1.473. PMID   15012217.
  5. 1 2 Negron L, Patchett ML, Parker EJ (2011). "Expression, Purification, and Characterisation of Dehydroquinate Synthase from Pyrococcus furiosus". Enzyme Research. 2011: 134893. doi: 10.4061/2011/134893 . PMC   3092513 . PMID   21603259.
  6. Arora Verasztó, H; Logotheti, M; Albrecht, R; Leitner, A; Zhu, H; Hartmann, MD (6 July 2020). "Architecture and functional dynamics of the pentafunctional AROM complex". Nature Chemical Biology. 16 (9): 973–978. doi:10.1038/s41589-020-0587-9. PMID   32632294. S2CID   220375879.

Further reading