:3-Deoxy-D-arabino-heptulosonic acid 7-phosphate

{{DISPLAYTITLE:3-Deoxy-D-arabino-heptulosonic acid 7-phosphate}}

{{Chembox

| Name= 3-Deoxy-{{small|D}}-arabino-heptulosonic acid 7-phosphate

| ImageFile = 3-Deoxy-D-arabino-heptulosonic acid 7-phosphate Fischer.svg

| ImageSize = 150px

| ImageAlt = Chemical structure of 3-deoxy-D-arabino-heptulosonic acid 7-phosphate (DAHP).

| ImageCaption = Fischer projection of DAHP

| IUPACName = 3-Deoxy-7-O-phosphono-{{small|D}}-arabino-hept-2-ulosonic acid

| SystematicName = (4R,5S,6R)-4,5,6-Trihydroxy-2-oxo-7-(phosphonooxy)heptanoic acid

| OtherNames = 3-Deoxy-{{small|D}}-arabino-heptulosonic acid 7-phosphate
3-Deoxy-{{small|D}}-arabino-heptulosonate-7-phosphate
DAHP
7-Phospho-2-dehydro-3-deoxy-{{small|D}}-arabino-heptonate

|Section1={{Chembox Identifiers

| CASNo = 2627-73-8

| ChemSpiderID = 141160

| InChI = 1/C7H13O10P/c8-3(1-4(9)7(12)13)6(11)5(10)2-17-18(14,15)16/h3,5-6,8,10-11H,1-2H2,(H,12,13)(H2,14,15,16)/t3-,5-,6+/m1/s1

| InChIKey = PJWIPEXIFFQAQZ-PUFIMZNGBD

| StdInChI = 1S/C7H13O10P/c8-3(1-4(9)7(12)13)6(11)5(10)2-17-18(14,15)16/h3,5-6,8,10-11H,1-2H2,(H,12,13)(H2,14,15,16)/t3-,5-,6+/m1/s1

| StdInChIKey = PJWIPEXIFFQAQZ-PUFIMZNGSA-N

| PubChem = 160647

| SMILES = C([C@H]([C@@H]([C@@H](COP(=O)(O)O)O)O)O)C(=O)C(=O)O

}}

|Section2={{Chembox Properties

| C=7 | H=13 | O=10 | P=1

| Appearance =

| Density =

| MeltingPt =

| BoilingPt =

| Solubility =

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|Section3={{Chembox Hazards

| MainHazards =

| FlashPt =

| AutoignitionPt =

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}}

3-Deoxy-{{small|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.

Phosphoenolpyruvate and erythrose-4-phosphate react to form 3-deoxy-{{small|D}}-arabino-heptulosonate-7-phosphate (DAHP), in a reaction catalyzed by the enzyme DAHP synthase.

:File:DAHP synthase reaction.svg{{clear left}}

DAHP is then transformed to 3-dehydroquinate (DHQ), in a reaction catalyzed by DHQ synthase. Although this reaction requires nicotinamide adenine dinucleotide (NAD) as a cofactor, the enzymic mechanism regenerates it, resulting in the net use of no NAD.

:File:Reaction catalyzed by 3-dehydroquinate synthase.svg catalyzed by 3-dehydroquinate synthase.]]{{clear left}}

The mechanism of ring closure is complex, but involves an aldol condensation at C-2 and C-7.

Metabolic engineering has improved production of DAHP by Escherichia coli.{{cite journal | author = Patnaik, R. | author2 = Liao, J. | name-list-style = amp | year = 1994 | title = Engineering of Escherichia coli central metabolism for aromatic metabolite production with near theoretical yield | journal = Appl. Environ. Microbiol. | volume = 60 | issue = 11 | pages = 3903–3908 | doi = 10.1128/AEM.60.11.3903-3908.1994 | pmid = 7993080 | pmc = 201913| bibcode = 1994ApEnM..60.3903P }} The first step, condensation of 3-deoxy-{{small|D}}-arabino-heptulosonic acid 7-phosphate (DAHP) from PEP/E4P, uses three isoenzymes AroF, AroG, and AroH.{{cite journal | doi = 10.1002/bit.260460409 | title = Pathway engineering for production of aromatics inEscherichia coli: Confirmation of stoichiometric analysis by independent modulation of AroG, TktA, and Pps activities | year = 1995 | last1 = Patnaik | first1 = Ranjan | last2 = Spitzer | first2 = Richard G. | last3 = Liao | first3 = James C. | journal = Biotechnology and Bioengineering | volume = 46 | issue = 4 | pages = 361–70 | pmid = 18623323| s2cid = 25862511 }} Each one of these has its synthesis regulated from tyrosine, phenylalanine, and tryptophan, respectively. These isoenzymes all have the ability to help regulate synthesis of DAHP by the method of feedback inhibition. This acts in the cell by monitoring the concentrations of each of the three aromatic amino acids. When there is too much of any one of them, that one will allosterically control the DAHP synthetase by “turning it off”. With the first step of the common pathway shut off, synthesis of the three amino acids can not proceed. The rest of the enzymes is in the common pathway (conversion of DAHP to chorismate).

:File:DAHP pathway.jpg. Abbreviations: GLU: glucose, G6P: Glucose 6-phosphate, PEP: Phosphoenolpyruvate, PYR: Pyruvate, F6P: Fructose 6-phosphate, P5P: Pentose 5-phosphate (ribose or xylulose 5-phosphate) T3P: Glyceraldehyde 3-phosphate, S7P: Sedoheptulose 7-phosphate, E4P: Erythrose-4-phosphate, PPS: PEP synthase.]]{{clear left}}