3hj6

Publication Abstract from PubMed

Fructokinase (FRK; EC 2.7.1.4) catalyzes the phosphorylation of d-fructose to d-fructose 6-phosphate (F6P). This irreversible and near rate-limiting step is a central and regulatory process in plants and bacteria, which channels fructose into a metabolically active state for glycolysis. Towards understanding the mechanism of FRK, here we report the crystal structure of a FRK homolog from a thermohalophilic bacterium Halothermothrixorenii (Hore_18220 in sequence databases). The structure of the Hore_18220 protein reveals a catalytic domain with a Rossmann-like fold and a beta-sheet "lid" for dimerization. Based on comparison of Hore_18220 to structures of related proteins, we propose its mechanism of action, in which the lid serves to regulate access to the substrate binding sites. Close relationship of Hore_18220 and plant FRK enzymes allows us to propose a model for the structure and function of FRKs.

Crystal structure of a fructokinase homolog from Halothermothrix orenii.,Chua TK, Seetharaman J, Kasprzak JM, Ng C, Patel BK, Love C, Bujnicki JM, Sivaraman J J Struct Biol. 2010 Sep;171(3):397-401. Epub 2010 May 21. PMID:20493950^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.