Pyruvate phosphate dikinase: Difference between revisions
| Line 8: | Line 8: | ||
| | | | ||
Pyruvate phosphate dikinase (PPDK) catalyzes the inter-conversion of adenosine triphosphate (ATP), P<sub>i</sub>, and pyruvate with adenine monophosphate (AMP), pyrophosphate (PP<sub>i</sub>, and phosphoenolpyruvate (PEP) in the presence of Mg<sup>2+</sup> and K<sup>+</sup>/Na<sup>+</sup>. The three-step reversible reaction proceeds via phosphoenzyme and pyrophosphoenzyme intermediates with a histidine residue serving as the phosphocarrier: | Pyruvate phosphate dikinase (PPDK) catalyzes the inter-conversion of adenosine triphosphate (ATP), P<sub>i</sub>, and pyruvate with adenine monophosphate (AMP), pyrophosphate (PP<sub>i</sub>, and phosphoenolpyruvate (PEP) in the presence of Mg<sup>2+</sup> and K<sup>+</sup>/Na<sup>+</sup>. The three-step reversible reaction proceeds via phosphoenzyme and pyrophosphoenzyme intermediates with a histidine residue serving as the phosphocarrier: | ||
1. PPDK-His + PEP ⇄ PPDK-His~PO<sub>3</sub> + pyruvate | 1. PPDK-His + PEP ⇄ PPDK-His~PO<sub>3</sub> + pyruvate | ||
2. PPDK-His~PO<sub>3</sub> + P<sub>2</sub>O<sub>7</sub> ⇄ PPDK-His~P<sub>2</sub>O<sub>7</sub> + PO<sub>3</sub> | 2. PPDK-His~PO<sub>3</sub> + P<sub>2</sub>O<sub>7</sub> ⇄ PPDK-His~P<sub>2</sub>O<sub>7</sub> + PO<sub>3</sub> | ||