This product is a recombinant fragment of human Riboflavin kinase (RFK), spanning residues 1-155, designed for structural and biochemical studies. It represents a stable and soluble unit of the enzyme, which catalyzes the phosphorylation of riboflavin to form flavin mononucleotide (FMN), a critical step in flavin adenine dinucleotide (FAD) biosynthesis.

Riboflavin kinase (EC 2.7.1.26), encoded by the RFK gene in humans, functions as an ATP:riboflavin 5'-phosphotransferase to produce FMN, making it the rate-limiting enzyme in FAD synthesis. It plays an essential role in TNF-induced reactive oxygen species (ROS) production by physically and functionally coupling TNFRSF1A to NADPH oxidase through interactions with both TNFRSF1A and CYBA. This coupling enhances FAD incorporation into NADPH oxidase, which is crucial for its assembly and activation. The protein is localized in the cytoplasm, underscoring its involvement in intracellular signaling and metabolic pathways.