entner–doudoroff pathway
DESCRIPTION
The Entner–Doudoroff pathway describes an alternate series of reactions that catabolize glucose to pyruvate using a set of enzymes different from those used in either glycolysis or the pentose phosphate pathway. Most bacteria use glycolysis and the pentose phosphate pathway. This pathway was firstly reported in 1952 by Michael Doudoroff (1911–1975) and Nathan Entner.TRANSCRIPT
Diagram of the Entner-Doudoroff pathway (KDPG: 2-keto-3-deoxy-6-phosphogluconate)
The EntnerDoudoroff pathway describes an alternate series of reactions that catabolize glucose to pyruvate using a set of enzymes different from those used in either glycolysis or the pentose phosphate pathway. Most bacteria use glycolysis and the pentose phosphate pathway. This pathway was firstly reported in 1952 by Michael Doudoroff (19111975) and Nathan Entner.[1]Distinct features of the EntnerDoudoroff pathway are that it:
Occurs only in prokaryotes.
Uses 6-phosphogluconate dehydrase and 2-keto-3-deoxyphosphogluconate aldolase to create pyruvates from glucose.
Has a net yield of 1 ATP for every glucose molecule processed, as well as 1 NADH and 1 NADPH. By comparison, glycolysis has a net yield of 2 ATP and 2 NADH for every one glucose molecule processed.
Organisms that utilize the Entner-Doudoroff pathway
All archae use the Entner-Doudoroff pathway rather than classic glycolysis.[2]There are a few bacteria that substitute classic glycolysis with the Entner-Doudoroff Pathway. They may lack enzymes essential for glycolysis, such as phosphofructokinase-1. This pathway is generally found in Pseudomonas, Rhizobium, Azotobacter, Agrobacterium, and a few other gram-negative genera. Very few gram-positive bacteria have this pathway, with Enterococcus faecalis being a rare exception.[3] Most organisms that use the pathway are aerobes due to the low ATP yield per glucose.[4] Pseudomonas,[5] a genus of Gram-negative bacteria
Azotobacter,[6] a genus of Gram-negative bacteria
Rhizobium,[7] a genus of Gram-negative bacteria
Agrobacterium,[8] a genus of Gram-negative bacteria
Escherichia coli,[5] a Gram-negative bacterium
Enterococcus faecalis,[9] a Gram-positive bacterium
Zymomonas mobilis,[4] a Gram-negative facultative anaerobe Xanthomonas campestris,[10] a Gram negative bacterium which uses this pathway as main pathway for providing energy.