Phosphoglycerate kinase

Phosphoglycerate kinase is a transferase enzyme used in the seventh step of glycolysis. It transfers a phosphate group from 1,3-bisphosphoglycerate to ADP, forming ATP and 3-Phosphoglycerate.

Phosphoglycerate kinase (PGK) is an enzyme that catalyses the formation of ATP to ADP and vice versa. In the second step of the second phase in glycolysis, 1,3-bisphosphoglycerate is converted to 3-phosphoglycerate, forming one molecule of ATP. If the reverse were to occur, one molecule of ADP would be formed. This reaction is essential in most cells for the generation of ATP in aerobes, for fermentation in anaerobes and for carbon fixation in plants.

PGK is found in all living organisms and its sequence has been highly conserved throughout evolution. The enzyme exists as a monomer containing two nearly equal-sized domains that correspond to the N- and C-termini of the protein. 3-phosphoglycerate (3-PG) binds to the N-terminal, while the nucleotide substrates, MgATP or MgADP, bind to the C-terminal domain of the enzyme. This extended two-domain structure is associated with large-scale 'hinge-bending' conformational changes, similar to those found in hexokinase. At the core of each domain is a 6-stranded parallel beta-sheet surrounded by alpha helices. The two lobes are capable of folding independently, consistent with the presence of intermediates on the folding pathway with a single domain folded.

Phosphoglycerate kinase (PGK) deficiency is associated with haemolytic anaemia and mental disorders in humans.

Human proteins containing this domain
PGK1;     PGK2;