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Entner–Doudoroff pathway AI simulator
(@Entner–Doudoroff pathway_simulator)
Hub AI
Entner–Doudoroff pathway AI simulator
(@Entner–Doudoroff pathway_simulator)
Entner–Doudoroff pathway
The Entner–Doudoroff pathway (ED 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, 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 (barley) uses the Entner–Doudoroff pathway.
Distinct features of the Entner–Doudoroff pathway are that it:
Archaea have variants of the Entner–Doudoroff Pathway. These variants are called the semiphosphorylative ED (spED) and the nonphosphorylative ED (npED):
Some archaea such as Crenarchaeota Sul. solfataricus and Tpt. tenax have what is called branched ED. In branched ED, the organism have both spED and npED that are both operative and work in parallel.
There are several bacteria that use the Entner–Doudoroff pathway for metabolism of glucose and are unable to catabolize via glycolysis (e.g., therefore lacking essential glycolytic enzymes such as phosphofructokinase as seen in Pseudomonas). Genera in which the pathway is prominent include Gram-negative,[citation needed] as listed below, Gram-positive bacteria such as Enterococcus faecalis,[full citation needed][page needed][better source needed] as well as several in the Archaea, the second distinct branch of the prokaryotes (and the "third domain of life", after the prokaryotic Eubacteria and the eukaryotes). Due to the low energy yield of the ED pathway, anaerobic bacteria seem to mainly use glycolysis while aerobic and facultative anaerobes are more likely to have the ED pathway. This is thought to be due to the fact that aerobic and facultative anaerobes have other non-glycolytic pathways for creating ATP such as oxidative phosphorylation. Thus, the ED pathway is favored due to the lesser amounts of proteins required. While anaerobic bacteria must rely on the glycolysis pathway to create a greater percentage of their required ATP; thus, its 2 ATP production is more favored over the ED pathway's 1 ATP production.
Examples of bacteria using the pathway are:
To date, there is evidence of Eukaryotes using the pathway, suggesting it may be more widespread than previously thought:
The Entner–Doudoroff pathway is present in many species of Archaea (caveat, see following), whose metabolisms "resemble... in [their] complexity those of Bacteria and lower Eukarya", and often include both this pathway and the Embden–Meyerhof–Parnas pathway of glycolysis, except most often as unique, modified variants.
Entner–Doudoroff pathway
The Entner–Doudoroff pathway (ED 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, 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 (barley) uses the Entner–Doudoroff pathway.
Distinct features of the Entner–Doudoroff pathway are that it:
Archaea have variants of the Entner–Doudoroff Pathway. These variants are called the semiphosphorylative ED (spED) and the nonphosphorylative ED (npED):
Some archaea such as Crenarchaeota Sul. solfataricus and Tpt. tenax have what is called branched ED. In branched ED, the organism have both spED and npED that are both operative and work in parallel.
There are several bacteria that use the Entner–Doudoroff pathway for metabolism of glucose and are unable to catabolize via glycolysis (e.g., therefore lacking essential glycolytic enzymes such as phosphofructokinase as seen in Pseudomonas). Genera in which the pathway is prominent include Gram-negative,[citation needed] as listed below, Gram-positive bacteria such as Enterococcus faecalis,[full citation needed][page needed][better source needed] as well as several in the Archaea, the second distinct branch of the prokaryotes (and the "third domain of life", after the prokaryotic Eubacteria and the eukaryotes). Due to the low energy yield of the ED pathway, anaerobic bacteria seem to mainly use glycolysis while aerobic and facultative anaerobes are more likely to have the ED pathway. This is thought to be due to the fact that aerobic and facultative anaerobes have other non-glycolytic pathways for creating ATP such as oxidative phosphorylation. Thus, the ED pathway is favored due to the lesser amounts of proteins required. While anaerobic bacteria must rely on the glycolysis pathway to create a greater percentage of their required ATP; thus, its 2 ATP production is more favored over the ED pathway's 1 ATP production.
Examples of bacteria using the pathway are:
To date, there is evidence of Eukaryotes using the pathway, suggesting it may be more widespread than previously thought:
The Entner–Doudoroff pathway is present in many species of Archaea (caveat, see following), whose metabolisms "resemble... in [their] complexity those of Bacteria and lower Eukarya", and often include both this pathway and the Embden–Meyerhof–Parnas pathway of glycolysis, except most often as unique, modified variants.
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