The Entner–Doudoroff pathway is a metabolic pathway that is most notable in Gram-negative bacteria, certain Gram-positive bacteria and archaea. Glucose is the substrate in the ED pathway and through a series of enzyme assisted chemical reactions it is catabolized into pyruvate. Entner and Doudoroff (1952) and MacGee and Doudoroff (1954) first reported the ED pathway in the bacterium Pseudomonas saccharophila. While originally thought to be just an alternative to glycolysis (EMP) and the pentose phosphate pathway (PPP), some studies now suggest that the original role of the EMP may have originally been about anabolism and repurposed over time to catabolism, meaning the ED pathway may be the older pathway. Recent studies have also shown the prevalence of the ED pathway may be more widespread than first predicted with evidence supporting the presence of the pathway in cyanobacteria, ferns, algae, mosses, and plants. Specifically, there is direct evidence that Hordeum vulgare uses the Entner–Doudoroff pathway.
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. With the chemical formula H(O)CCH(OH)CH2OPO32-, this anion is a monophosphate ester of glyceraldehyde.
3-Phosphoglyceric acid (3PG, 3-PGA, or PGA) is the conjugate acid of 3-phosphoglycerate or glycerate 3-phosphate (GP or G3P). This glycerate is a biochemically significant metabolic intermediate in both glycolysis and the Calvin-Benson cycle. The anion is often termed as PGA when referring to the Calvin-Benson cycle. In the Calvin-Benson cycle, 3-phosphoglycerate is typically the product of the spontaneous scission of an unstable 6-carbon intermediate formed upon CO2 fixation. Thus, two equivalents of 3-phosphoglycerate are produced for each molecule of CO2 that is fixed. In glycolysis, 3-phosphoglycerate is an intermediate following the dephosphorylation (reduction) of 1,3-bisphosphoglycerate.
1,3-Bisphosphoglyceric acid (1,3-Bisphosphoglycerate or 1,3BPG) is a 3-carbon organic molecule present in most, if not all, living organisms. It primarily exists as a metabolic intermediate in both glycolysis during respiration and the Calvin cycle during photosynthesis. 1,3BPG is a transitional stage between glycerate 3-phosphate and glyceraldehyde 3-phosphate during the fixation/reduction of CO2. 1,3BPG is also a precursor to 2,3-bisphosphoglycerate which in turn is a reaction intermediate in the glycolytic pathway.
Phosphoglycerate kinase is an enzyme that catalyzes the reversible transfer of a phosphate group from 1,3-bisphosphoglycerate (1,3-BPG) to ADP producing 3-phosphoglycerate (3-PG) and ATP :
Phosphoglycerate mutase (PGM) is any enzyme that catalyzes step 8 of glycolysis - the internal transfer of a phosphate group from C-3 to C-2 which results in the conversion of 3-phosphoglycerate (3PG) to 2-phosphoglycerate (2PG) through a 2,3-bisphosphoglycerate intermediate. These enzymes are categorized into the two distinct classes of either cofactor-dependent (dPGM) or cofactor-independent (iPGM). The dPGM enzyme is composed of approximately 250 amino acids and is found in all vertebrates as well as in some invertebrates, fungi, and bacteria. The iPGM class is found in all plants and algae as well as in some invertebrate, fungi, and Gram-positive bacteria. This class of PGM enzyme shares the same superfamily as alkaline phosphatase.
Glucose-1,6-bisphosphate synthase is a type of enzyme called a phosphotransferase and is involved in mammalian starch and sucrose metabolism. It catalyzes the transfer of a phosphate group from 1,3-bisphosphoglycerate to glucose-1-phosphate, yielding 3-phosphoglycerate and glucose-1,6-bisphosphate.
The enzyme 3-phosphoglycerate phosphatase (EC 3.1.3.38) catalyzes the reaction
The enzyme ADP-phosphoglycerate phosphatase (EC 3.1.3.28) catalyzes the reaction
In enzymology, a bisphosphoglycerate phosphatase (EC 3.1.3.13) is an enzyme that catalyzes the chemical reaction
The enzyme mannosyl-3-phosphoglycerate phosphatase (EC 3.1.3.70) catalyzes the reaction
The enzyme methylphosphothioglycerate phosphatase (EC 3.1.3.14) catalyzes the reaction
In enzymology, a mannosyl-3-phosphoglycerate synthase is an enzyme that catalyzes the chemical reaction
In enzymology, a glycerate kinase is an enzyme that catalyzes the chemical reaction
In enzymology, a phosphoglycerate kinase (GTP) (EC 2.7.2.10) is an enzyme that catalyzes the chemical reaction
Mannosylglycerate synthase is an enzyme with systematic name GDP-mannose:D-glycerate 2-alpha-D-mannosyltransferase. This enzyme catalyses the following chemical reaction
Glycerate 2-kinase is an enzyme with systematic name ATP:D-glycerate 2-phosphotransferase. This enzyme catalyses the following chemical reaction
2,3-Bisphosphoglycerate 3-phosphatase (EC 3.1.3.80, MIPP1, 2,3-BPG 3-phosphatase) is an enzyme with systematic name 2,3-bisphospho-D-glycerate 3-phosphohydrolase. This enzyme catalyses the following reaction:
Glucosyl-3-phosphoglycerate phosphatase (EC 3.1.3.85, GpgP protein) is an enzyme with systematic name α-D-glucosyl-3-phospho-D-glycerate phosphohydrolase. This enzyme catalyses the following chemical reaction
2-Phosphoglycolate (chemical formula C2H2O6P3-; also known as phosphoglycolate, 2-PG, or PG) is a natural metabolic product of the oxygenase reaction mediated by the enzyme ribulose 1,5-bisphosphate carboxylase (RuBisCo).
