3-phosphoglycerate kinase

3-Phosphoglycerate kinase is an enzyme that plays a crucial role in the process of glycolysis. It is responsible for the conversion of 1,3-bisphosphoglycerate (1,3-BPG) to 3-phosphoglycerate (3-PG) during the seventh step of glycolysis, releasing adenosine triphosphate (ATP) in the process.

Function

The primary function of 3-phosphoglycerate kinase is to facilitate the transfer of a phosphate group from 1,3-BPG to adenosine diphosphate (ADP), producing ATP and 3-PG. This reaction is exergonic, meaning it releases energy, which is captured in the form of ATP. This step is one of the two substrate-level phosphorylation steps in glycolysis where ATP is directly synthesized.

Structure

3-Phosphoglycerate kinase is a monomeric enzyme composed of a single polypeptide chain. The enzyme has two domains, a large domain that binds 1,3-BPG and a small domain that binds ADP. The two domains are connected by a hinge region that allows the enzyme to undergo a large conformational change during the catalytic cycle.

Clinical significance

Mutations in the gene encoding 3-phosphoglycerate kinase can lead to 3-phosphoglycerate kinase deficiency, a rare X-linked recessive disorder. Symptoms of this disorder can include hemolytic anemia, muscle weakness, and mental retardation.

See also

• Glycolysis
• Enzyme
• Adenosine triphosphate