Fructokinase
| Fructokinase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Fructokinase dimer, Bacillus subtilis | |||||||||
| Identifiers | |||||||||
| EC no. | 2.7.1.4 | ||||||||
| CAS no. | 9030-51-7 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
Fructokinase (EC 2.7.1.4), also known as D-fructokinase, is an enzyme that transfers a phosphate group from adenosine triphosphate (ATP) to D-fructose, producing D-fructose 6-phosphate. Its systematic name is ATP:D-fructose 6-phosphotransferase. In enzyme nomenclature, it is distinct from ketohexokinase (EC 2.7.1.3), which instead produces D-fructose 1-phosphate.
Role in plants and bacteria
Fructokinase has been characterized from various organisms, such as pea (Pisum sativum) seeds, avocado (Persera americana) fruit, and maize (Zea mays) kernels, and many more.
Specifically, fructokinase may also regulate starch synthesis in conjunction with sucrose synthase. There are also two divergent fructokinase genes that are differentially expressed and which also have different enzymatic properties such as those found in tomatoes. In tomatoes, fructokinase 1 (Frk 1) mRNA is expressed at a constant level during fruit development. However, fructokinase 2 (Frk 2) mRNA has a high expression level in young tomato fruit but then decreases during the later stages of fruit development. Frk 2 has a higher affinity for fructose than Frk 1 but Frk 2 activity is inhibited by high levels of fructose, whereas Frk 1 activity is not.
In Sinorhizobium meliloti, a common gram-soil bacterium, fructokinase is also used in the metabolism of mannitol and sorbitol, in addition to the metabolism of fructose.
Reaction
Fructokinase catalyzes the following reaction:
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See also
References
- 1 2 3 "EC 2.7.1.4". IUBMB Enzyme Nomenclature. International Union of Biochemistry and Molecular Biology. Retrieved 10 September 2026.
- ↑ "EC 2.7.1.3". IUBMB Enzyme Nomenclature. International Union of Biochemistry and Molecular Biology. Retrieved 10 September 2026.
- 1 2 3 Odanaka S, Bennett AB, Kanayama Y (July 2002). "Distinct physiological roles of fructokinase isozymes revealed by gene-specific suppression of Frk1 and Frk2 expression in tomato". Plant Physiol. 129 (3): 1119–26. doi:10.1104/pp.000703. PMC 166506. PMID 12114566.
- ↑ Gardiol A, Arias A, Cerveñansky C, Gaggero C, Martínez-Drets G (October 1980). "Biochemical characterization of a fructokinase mutant of Rhizobium meliloti". J. Bacteriol. 144 (1): 12–6. doi:10.1128/jb.144.1.12-16.1980. PMC 294576. PMID 6252186.
External links
- Fructokinases at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
