Sandbox 160
From Proteopedia
Introduction
Glyceraldehyde 3-Phosphate dehydrogenase (GAPDH) is an Oxidoreductase enzyme and is involved in many important biochemical reactions. This protein is responsible for catalyzing the conversion of glyceraldeyde 3-Phosphate into 1,3-Biphosphoglycerate in a two step coupled mechanism. This conversion occurs during step 6 or the beginning of the "payoff phase" of glycolysis (the second half of the entire process) in which ATP and NADH is produced. A total of 2 NADH and 4 ATP are produced during this phase for a net gain of 2 NADH and 2 ATP for the entire glycolysis pathway per glucose.
Structure & Function
The enzyme contains a NAD+ group which functions as a hydrogen acceptor during the course of the reaction which is bound to a Rossman fold. During the catalysis of glyceraldehyde 3-phosphate to 1,3-biphosphoglycerate a hydride ion is enzymatically transferred from the aldehyde group of glyceraldehyde 3-phosphate to the nicotinamide ring of NAD+ reducing it to NADH. The active site of GAPDH contains a cysteine residue which reacts with the glyceraldehyde 3-phosphate molecule through its -SH group. The substrate is covalently bound during the reaction through its aldehyde group to the -SH group and the reaction produces a thiohemiacetal. The of the molecule is illustrated below.
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| 1vc2, resolution 2.60Å () | |||||||||
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| Activity: | Glyceraldehyde-3-phosphate dehydrogenase (phosphorylating), with EC number 1.2.1.12 | ||||||||
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| Resources: | FirstGlance, OCA, RCSB, PDBsum, TOPSAN | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
