-!- In the direction shown, the enzyme is phosphorylated by 3-phosphoglyceroyl phosphate to give phosphoenzyme and 3-phosphoglycerate. -!- The latter is rephosphorylated by the enzyme to yield 2,3- diphosphoglycerate, but this reaction is slowed down by dissociation of 3-phosphoglycerate from the enzyme, which is therefore more active in the presence of added 3-phosphoglycerate. -!- Also catalyzes, slowly, the reaction of EC 5.4.2.12. -!- Formerly EC 2.7.5.4.

-!- The enzymes from vertebrates, platyhelminths, mollusks, annelids, crustaceans, insects, algae, some fungi, yeast and some bacteria (particularly Gram-negative) require 2,3-bisphospho-D-glycerate as a cofactor. -!- The enzyme is activated by 2,3-bisphospho-D-glycerate by transferring a phosphate to histidine (His(10) in man and Escherichia coli, His(8) in Saccharomyces cerevisiae). -!- This phosphate can be transferred to the free OH of 2-phospho-D- glycerate, followed by transfer of the phosphate already on the phosphoglycerate back to the histidine. -!- Cf. EC 5.4.2.12. -!- The enzyme has no requirement for metal ions. -!- This enzyme also catalyze, slowly, the reactions of EC 5.4.2.4. -!- Formerly EC 2.7.5.3 and EC 5.4.2.1.