nucleotide-binding domain (NBD) of D-ribulokinase FGGY and similar proteins
The subfamily includes vertebrate D-ribulokinase FGGY (also known as FGGY carbohydrate kinase domain-containing protein) and similar proteins, such as Saccharomyces cerevisiae D-ribulokinase YDR109C, Yersinia Pseudotuberculosis uncharacterized carbohydrate kinase that has been named glyerol/xylulose kinase. D-ribulokinase (EC 2.7.1.47) catalyzes ATP-dependent phosphorylation of D-ribulose at C-5 to form D-ribulose 5-phosphate. It is postulated to function in a metabolite repair mechanism by preventing toxic accumulation of free D-ribulose formed by non-specific phosphatase activities. Alternatively, D-ribulokinase may play a role in regulating D-ribulose 5-phosphate recycling in the pentose phosphate pathway.
Comment:catalytic residues (Asp, Thr, Asp) conserved in the FGGY family
Comment:Two Asp residues probably form a metal cofactor binding site and the second Asp residue acts as a catalytic base.
Comment:It has been proposed that the first Asp coordinates and positions the MgATP, and (in concert with the Mg2+) stabilizes the ADP leaving group during the phospho transfer. The second Asp would act as a general base during catalysis, assisting the removal of a proton from the attacking hydroxyl group. The Thr could stabilize the transition state.
Jiyao W et al.(2023). "The conserved domain database in 2023.",