Phosphorylation of glycerate by glycerate kinase is a key biochemical step connected with central carbon metabolism.
Glycerate kinases have been characterized from all domains of life: Bacteria, Eukarya and Archaea. Two distinct classes of glycerate kinases were identified based on the reaction product - either 3-phosphoglycerate (3-PG) or 2-phoshoglycerate (2-PG). Despite the classification, 2-PG and 3-PG are easily interconverted by a phosphoglycerate mutase (PGM).
There are also two protein classes of putative glycerate kinases based on structure similarities. These two separate fold families have no significant sequence similarity despite their identical biochemical activities. One family contains enzymes from bacterial species. The second family consists of proteins from eukaryotes and archaea in addition to several different bacterial species.
Our structure belongs to the first structural class and is represented by glxK from Escherichia coli and glycerate kinase from Neisseria meningitidis. The N-terminal domain of the structure contains a 6-stranded parallel β-sheet and several surrounding helices with Rossmann-like topology. The C-terminal domain contains a central 5-stranded mixed β-sheet and 2 pairs of surrounding helices. The active site is likely to be inside the cleft between the two domains.