The Entner-Doudoroff pathway: history, physiology and molecular biology.

The Entner-Doudoroff pathway is now known to be very widely distributed in nature. Biochemical and physiological studies show that the Entner-Doudoroff pathway can operate in a linear and catabolic mode, in a 'cyclic' mode, in a modified mode involving non-phosphorylated intermediates, or in alternative modes involving C1 metabolism and anabolism. Molecular and genetic analyses of the Entner-Doudoroff pathway in Zymomonas mobilis, Escherichia coli and Pseudomonas aeruginosa have led to an improved understanding of some fundamental aspects of metabolic controls. It can be argued that the Entner-Doudoroff pathway is more primitive than Embden-Meyerhof-Parnas glycolysis.