2vbs
Riboflavin kinase Mj0056 from Methanocaldococcus jannaschii in complex with PO4
Structural highlights
FunctionRIFK_METJA Catalyzes the CTP-dependent phosphorylation of riboflavin (vitamin B2) to form flavin mononucleotide (FMN). Can also utilize UTP as the phosphate donor, although less efficiently, and it is unclear if ATP and GTP can also serve as substrates (PubMed:18245297) or not (PubMed:18073108).[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedProteins of the cradle-loop barrel metafold are formed by duplication of a conserved betaalphabeta-element, suggesting a common evolutionary origin from an ancestral group of nucleic acid-binding proteins. The basal fold within this metafold, the RIFT barrel, is also found in a wide range of enzymes, whose homologous relationship with the nucleic acid-binding group is unclear. We have characterized a protein family that is intermediate in sequence and structure between the basal group of cradle-loop barrels and one family of RIFT-barrel enzymes, the riboflavin kinases. We report the structure, substrate-binding mode, and catalytic activity for one of these proteins, Methanocaldococcus jannaschii Mj0056, which is an archaeal riboflavin kinase. Mj0056 is unusual in utilizing CTP rather than ATP as the donor nucleotide, and sequence conservation in the relevant residues suggests that this is a general feature of archaeal riboflavin kinases. A CTP-dependent archaeal riboflavin kinase forms a bridge in the evolution of cradle-loop barrels.,Ammelburg M, Hartmann MD, Djuranovic S, Alva V, Koretke KK, Martin J, Sauer G, Truffault V, Zeth K, Lupas AN, Coles M Structure. 2007 Dec;15(12):1577-90. PMID:18073108[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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