the enzyme is part of the modified glycolytic pathway of Thermoproteus tenax. In the classical Embden–Meyerhof–Parnas glycolysis, as found in Eucarya and Bacteria, the oxidation of D-glyceraldehyde 3-phosphate is coupled to phosphorylation to yield 1,3-diphosphoglycerate, which in turn is utilized by phosphoglycerate kinase giving 3-phosphoglycerate and ATP. These steps are reversible and non-regulated in the common Embden–Meyerhof–Parnas pathway. In contrast, the direct and irreversible oxidation of D-glyceraldehyde 3-phosphate to 3-phospho-D-glycerate without production of ATP is catalysed either by non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase or by glyceraldehyde-3-phosphate ferredoxin oxidoreductase (
EC 1.2.1.59). The non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase/glyceraldehyde-3-phosphate ferredoxin oxidoreductase substitution in the catabolic Embden–Meyerhof–Parnas pathway avoids the production of the highly thermolabile compound 1,3-diphosphoglycerate and could minimize the pools of the thermolabile intermediates D-glyceraldehyde 3-phosphate and dihydroxyacetonphosphate by driving the carbon flow down the pathway and thus reducing the velocity of their heat destruction
