1n08
Crystal Structure of Schizosaccharomyces pombe Riboflavin Kinase Reveals a Novel ATP and Riboflavin Binding Fold
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OverviewOverview
The essential redox cofactors riboflavin monophosphate (FMN) and flavin, adenine dinucleotide (FAD) are synthesised from their precursor, riboflavin, in sequential reactions by the metal-dependent riboflavin, kinase and FAD synthetase. Here, we describe the 1.6A crystal structure of, the Schizosaccharomyces pombe riboflavin kinase. The enzyme represents a, novel family of phosphoryl transferring enzymes. It is a monomer, comprising a central beta-barrel clasped on one side by two C-terminal, helices that display an L-like shape. The opposite side of the beta-barrel, serves as a platform for substrate binding as demonstrated by complexes, with ADP and FMN. Formation of the ATP-binding site requires significant, rearrangements in a short alpha-helix as compared to the substrate free, form. The diphosphate moiety of ADP is covered by the glycine-rich flap I, formed from parts of this alpha-helix. In contrast, no significant changes, are observed upon binding of riboflavin. The ribityl side-chain might be, covered by a rather flexible flap II. The unusual metal-binding site, involves, in addition to the ADP phosphates, only the strictly conserved, Thr45. This may explain the preference for zinc observed in vitro.
About this StructureAbout this Structure
1N08 is a Single protein structure of sequence from Schizosaccharomyces pombe with ZN and ADP as ligands. Active as Riboflavin kinase, with EC number 2.7.1.26 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of Schizosaccharomyces pombe riboflavin kinase reveals a novel ATP and riboflavin-binding fold., Bauer S, Kemter K, Bacher A, Huber R, Fischer M, Steinbacher S, J Mol Biol. 2003 Mar 7;326(5):1463-73. PMID:12595258
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