| Type: | Family | Name: | 2-phosphoglycerate kinase |
| Description: | Analysis of the metabolome of a number of methanogenic archaea revealed that they produced a number of unusual compounds of low molecular weight, one of which was cyclic 2,3-diphosphoglycerate (cDPG). This has been found to occur in several methanogens in high concentrations of up to 1 Molar. The highest intracellular concentrations of cDPG were detected in the hyperthermophilic methanogens Methanothermus fervidus(optimal growth temperature, 83 degrees C) and Methanopyrus kandleri(optimal growth temperature, 98 degrees C). Additionally, the intracellular concentration of cDPG increases with temperature up to the optimal growth temperature in M. fervidus. It has been proposed that cDPG is either used an energy store and/or is involved in the process of thermoadaption []. In M. fervidus cDPG is synthesized in two steps starting from 2-phosphoglycerate. In the first reaction, the 2-phosphoglycerate kinase (2PGK) phosphorylates 2-PG using ATP, resulting in 2,3-diphosphoglycerate (2,3-DPG) and ADP. The cDPG synthetase (cDPGS) catalyses the subsequent intramolecular cyclization of 2,3-DPG to cDPG, consuming a second molecule of ATP. Both 2PGK and cDPGS activities have been demonstrated in other cDPG-containing methanogens: Methanobacterium bryantii, Methanobacterium thermoautotrophicumand M. kandleri []. | Short Name: | 2-phosphoglycerate_kinase |
