NAD+-dependent glyceraldehyde-3-phosphate dehydrogenase from Thermoproteus tenax. The first identified archaeal member of the aldehyde dehydrogenase superfamily is a glycolytic enzyme with unusual regulatory properties.
The hyperthermophilic archaeum Thermoproteus tenax possesses two glyceraldehyde-3-phosphate dehydrogenases differing in cosubstrate specificity and phosphate dependence of the catalyzed reaction. NAD+-dependent glyceraldehyde-3-phosphate dehydrogenase catalyzes the phosphate-independent irreversible oxidation of D-glyceraldehyde 3-phosphate to 3-phosphoglycerate. The coding gene was cloned, sequenced, and expressed in Escherichia coli. Sequence comparisons showed no similarity to phosphorylating glyceraldehyde-3-phosphate dehydrogenases but revealed a relationship to aldehyde dehydrogenases, with the highest similarity to the subgroup of nonphosphorylating glyceraldehyde-3-phosphate dehydrogenases. The activity of the enzyme is affected by a series of metabolites. All effectors tested influence the affinity of the enzyme for its cosubstrate NAD+. Whereas NADP(H), NADH, and ATP reduce the affinity for the cosubstrate, AMP, ADP, glucose 1-phosphate, and fructose 6-phosphate increase the affinity for NAD+. Additionally, most of the effectors investigated induce cooperativity of NAD+ binding. The irreversible catabolic oxidation of glyceraldehyde 3-phosphate, the control of the enzyme by energy charge of the cell, and the regulation by intermediates of glycolysis and glucan degradation identify the NAD+-dependent glyceraldehyde-3-phosphate dehydrogenase as an integral constituent of glycolysis in T. tenax. Its regulatory properties substitute for those lacking in the reversible nonregulated pyrophosphate-dependent phosphofructokinase in this variant of the Embden-Meyerhof-Parnas pathway.
Brunner
N A
NA
Department of Microbiology, FB 9, Universit¿t-GH Essen, Universit¿tsstrasse 5, 45117 Essen, Germany.
Brinkmann
H
H
Siebers
B
B
Hensel
R
R
D000227:Adenine Nucleotides / Q000494:pharmacology; D000444:Aldehyde Dehydrogenase / Q000235:genetics; D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D019766:Genes, Archaeal; D005986:Glyceraldehyde 3-Phosphate / Q000378:metabolism; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D011994:Recombinant Proteins; D017386:Sequence Homology, Amino Acid; D019624:Thermoproteaceae / Q000145:classification / Q000201:enzymology / Q000235:genetics*
D000227:Adenine Nucleotides; D019843:Archaeal Proteins; D011994:Recombinant Proteins; D005986:Glyceraldehyde 3-Phosphate; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D000444:Aldehyde Dehydrogenase