EC Number   |
General Information |
Reference |
|---|
    2.7.1.26 | evolution |
different organisms, different regulatory strategies of RFKs, overview |
759167 |
| 2.7.1.26 | evolution |
eukaryotic FMNAT is related to phosphoadenosine phosphosulfate (PAPS) reductase family proteins and contains a core domain with a modified Rossman-fold topology and a C-terminal extension |
737678 |
| 2.7.1.26 | evolution |
whereas the N-terminal module of FADS lacks structural homology to eukaryotic FMNATs, the kinase module is homologous to monofunctional RFKs |
737357 |
| 2.7.1.26 | malfunction |
enzyme RFK downregulation alters expression profiles of clock-controlled metabolic-genes and destroys flavins protection on stroke treatments, while its activity reduction links to protein-energy malnutrition and thyroid hormones decrease |
759167 |
| 2.7.1.26 | metabolism |
biosynthesis of FMN and FAD from riboflavin (RF) involves two reactions: RF is first phosphorylated to FMN in an ATP-Mg2+-dependent reaction carried out by an ATP:riboflavin kinase (RFK), and then an FMN:ATP adenylyltransferase (FMNAT) transfers the adenylyl group from a second ATP molecule to FMN to yield FAD. In eukaryotes, these reactions are preferentially performed by two independent monofunctional enzymes, but in most prokaryotes, the two reactions are sequentially catalyzed by a bifunctional enzyme known as prokaryotic type I FAD synthetase (FADS). These bifunctional proteins are organized in two nearly independent modules with each one catalyzing one of the two activities |
760159 |
| 2.7.1.26 | more |
adenine and flavin nucleotide ligands cooperate in their binding to the RFK module |
760159 |
| 2.7.1.26 | more |
molecular dynamics simulations of riboflavin kinase domain bound to FMN, ADP, and Mg2+, structure-function analysis, flavin-binding site structure in the RFK module of CaFADS, overview |
737357 |
| 2.7.1.26 | more |
molecular dynamics simulations, structure-function analysis |
759167 |
| 2.7.1.26 | more |
residue E268 is the catalytic base of the kinase reaction. The salt bridge between E268 at the RFK site and R66 at the FMNAT-module is important for the riboflavinkinase activity. Cross-talk between the RFK- and FMNAT-modules of neighboring protomers in the CaFADS enzyme, and participation of R66 in the modulation of the geometry of the RFK active site during catalysis |
737771 |
| 2.7.1.26 | physiological function |
Enzymes known as bifunctional and bimodular prokaryotic type-I FAD synthetase (FADS) exhibit ATP:riboflavin kinase (RFK) and FMN:ATP adenylyltransferase (FMNAT) activities in their C-terminal and N-terminal modules, respectively, and produce flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). These act as cofactors of a plethora of flavoproteins in all organisms. Kinetics and thermodynamics of the protein-ligand interactions of riboflavin kinase activity of FAD synthetase from Corynebacterium ammoniagenes, overview. FMN synthesis is a key process that requires tight regulation. FMN production by CaFADS is highly regulated by substrate and product inhibition of its RFK activity to avoid overproduction even though the RF substrate might transiently increases in the media, where usually the amount of RF is considerably lower than that of FMN and particularly of FAD (either free or as part of flavoproteins) |
760159 |
