What is "phosphoglycerate kinase"

n. (context enzyme English) Any enzyme that catalyzes the transfer of a phosphate group between ATP and phosphoglycerate

Phosphoglycerate kinase (PGK) is an enzyme that catalyzes the reversible transfer of a phosphate group from 1,3-bisphosphoglycerate (1,3-BPG) to ADP producing 3-phosphoglycerate (3-PG) and ATP. Like all kinases it is a transferase. PGK is a major enzyme used in glycolysis, in the first ATP-generating step of the glycolytic pathway. In gluconeogenesis, the reaction catalyzed by PGK proceeds in the opposite direction, generating ADP and 1,3-BPG.

In humans, two isozymes of PGK have been so far identified, PGK1 and PGK2. The isozymes have 87-88% identical amino acid sequence identity and though they are structurally and functionally similar, they have different localizations: PGK2, encoded by an autosomal gene, is unique to meiotic and postmeiotic spermatogenic cells, while PGK1, encoded on the X-chromosome, is ubiquitously expressed in all cells.

In enzymology, a phosphoglycerate kinase (GTP) is an enzyme that catalyzes the chemical reaction

GTP + 3-phospho-D-glycerate $\rightleftharpoons$ GDP + 3-phospho-D-glyceroyl phosphate

Thus, the two substrates of this enzyme are GTP and 3-phospho-D-glycerate, whereas its two products are GDP and 3-phospho-D-glyceroyl phosphate.

This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups ( phosphotransferases) with a carboxy group as acceptor. The systematic name of this enzyme class is GTP:3-phospho-D-glycerate 1-phosphotransferase.