Fructokinase (), also known as -fructokinase, is an enzyme that transfers a phosphate group from adenosine triphosphate (ATP) to -fructose, producing -fructose 6-phosphate. Its systematic name is ATP:-fructose 6-phosphotransferase. In enzyme nomenclature, it is distinct from ketohexokinase (), which instead produces -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:
See also Hepatic fructokinase PFKL PFKM PFKP Glucokinase Hexokinase
References
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