EC Number |
General Information |
Reference |
---|
1.2.1.90 | physiological function |
enzyme GabD irreversibly oxidizes D-glyceraldehyde 3-phosphate (Ga3P) to 3-phospho-D-glycerate (3Pglycerate) using NAD+ or NADP+, thus resembling a non-phosphorylating Ga3PDHase. But the enzyme shows about 6fold higher Km value and three orders of magnitude higher catalytic efficiency with succinate semialdehyde (SSA) and NADP+. Indeed, the GabD protein identity corresponds to an SSA dehydrogenase (SSADHase, EC 1.2.1.16) |
-, 762770 |
1.2.1.90 | metabolism |
the enzyme is part of the modified EmbdenÂMeyerhofÂParnas pathway, the main route for carbohydrate metabolism in Thermoproteus tenax |
727454 |
1.2.1.90 | metabolism |
the enzyme is part of the modified glycolytic pathway of Thermoproteus tenax. In the classical EmbdenÂMeyerhofÂParnas 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 EmbdenÂMeyerhofÂParnas 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 EmbdenÂMeyerhofÂParnas 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 |
728132 |