Erythrose 4-phosphate is a

phosphate Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthop ...

of the simple sugar

erythrose Erythrose is a tetrose saccharide with the chemical formula C4H8O4. It has one aldehyde group, and is thus part of the aldose family. The natural isomer is D-erythrose; it is a diastereomer of D -threose. Erythrose was first isolated in 1849 ...

. It is an intermediate in the

pentose phosphate pathway The pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt or HMP shunt) is a metabolic pathway parallel to glycolysis. It generates NADPH and pentoses (five-carbon sugars) as well as ribose 5-ph ...

and the

Calvin cycle The Calvin cycle, light-independent reactions, bio synthetic phase, dark reactions, or photosynthetic carbon reduction (PCR) cycle of photosynthesis is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into ...

. The enzyme

transaldolase Transaldolase is an enzyme () of the non-oxidative phase of the pentose phosphate pathway. In humans, transaldolase is encoded by the ''TALDO1'' gene. The following chemical reaction is catalyzed by transaldolase: : sedoheptulose 7-phospha ...

catalyzes the formation of erythrose 4-phosphate and

fructose 6-phosphate Fructose 6-phosphate (sometimes called the Neuberg ester) is a derivative of fructose, which has been phosphorylated at the 6-hydroxy group. It is one of several possible fructosephosphates. The β-D-form of this compound is very common in cells ...

from

sedoheptulose 7-phosphate Sedoheptulose 7-phosphate is an intermediate in the pentose phosphate pathway. It is formed by transketolase and acted upon by transaldolase. Sedoheptulokinase is an enzyme that uses sedoheptulose and ATP to produce ADP and sedoheptulose 7-pho ...

and

glyceraldehyde 3-phosphate Glyceraldehyde 3-phosphate, also known as triose phosphate or 3-phosphoglyceraldehyde and abbreviated as G3P, GA3P, GADP, GAP, TP, GALP or PGAL, is a metabolite that occurs as an intermediate in several central pathways of all organisms.Nelson, D ...

. This reaction is a part of the non-oxidative phase of the pentose phosphate pathway. In the Calvin cycle, the enzyme

fructose-bisphosphate aldolase Fructose-bisphosphate aldolase (), often just aldolase, is an enzyme catalyzing a reversible reaction that splits the aldol, fructose 1,6-bisphosphate, into the triose phosphates dihydroxyacetone phosphate (DHAP) and glyceraldehyde 3-phosp ...

catalyzes the formation of sedoheptulose 1,7-bisphosphate from erythrose 4-phosphate and

dihydroxyacetone phosphate Dihydroxyacetone phosphate (DHAP, also glycerone phosphate in older texts) is the anion with the formula HOCH2C(O)CH2OPO32-. This anion is involved in many metabolic pathways, including the Calvin cycle in plants and glycolysis.Nelson, D. L.; Co ...

. In addition, it serves as a precursor in the biosynthesis of the aromatic amino acids

tyrosine -Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a conditionally essential amino acid with a polar side group. The word "tyrosine" is ...

phenylalanine Phenylalanine (symbol Phe or F) is an essential α-amino acid with the chemical formula, formula . It can be viewed as a benzyl group substituent, substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of ...

, and

tryptophan Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α-carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromat ...

. It is used in the first step of the

shikimate pathway The shikimate pathway (shikimic acid 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 (tryptophan, phenylalanine, and tyrosine) ...

. At this stage,

phosphoenolpyruvate Phosphoenolpyruvate (2-phosphoenolpyruvate, PEP) is the carboxylic acid derived from the enol of pyruvate and a phosphate anion. It exists as an anion. PEP is an important intermediate in biochemistry. It has the high-energy phosphate, highest-e ...

and erythrose-4-phosphate react to form

3-deoxy-D-arabinoheptulosonate-7-phosphate 3-Deoxy--''arabino''-heptulosonic acid 7-phosphate (DAHP) is a 7-carbon ulosonic acid. This compound is found in the Shikimic acid pathway, shikimic acid biosynthesis pathway and is an intermediate in the amino acid synthesis, production of aroma ...

(DAHP), in a reaction catalyzed by the enzyme

DAHP synthase 3-Deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) synthase () is the first enzyme in a series of metabolic Chemical reaction, reactions known as the shikimate pathway, which is responsible for the biosynthesis of the amino acids phenylalanine, ...

. :

It also used in 3-hydroxy-1-aminoacetone phosphate biosynthesis, which is a precursor of

vitamin B6 Vitamin B6 is one of the B vitamins, and is an essential nutrient for humans. The term essential nutrient refers to a group of six chemically similar compounds, i.e., "vitamers", which can be interconverted in biological systems. Its active f ...

in DXP-dependent pathway. Erythrose-4-phosphate dehydrogenase is used to produce erythronate-4-phosphate.

References

{{Pentose phosphate pathway intermediates Monosaccharide derivatives Organophosphates Pentose phosphate pathway