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Crystal structure of Schizosaccharomyces pombe riboflavin kinase reveals a novel ATP and riboflavin-binding fold
- Source :
- Journal of molecular biology. 326(5)
- Publication Year :
- 2003
-
Abstract
- 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.
- Subjects :
- Models, Molecular
Protein Folding
Stereochemistry
Flavin Mononucleotide
Protein Conformation
Riboflavin
Molecular Sequence Data
Flavoprotein
Flavin group
In Vitro Techniques
Riboflavin kinase
Crystallography, X-Ray
Riboflavin binding
Substrate Specificity
chemistry.chemical_compound
Adenosine Triphosphate
Structural Biology
Multienzyme Complexes
Schizosaccharomyces
Amino Acid Sequence
Molecular Biology
Flavin adenine dinucleotide
FAD synthetase
Binding Sites
biology
Sequence Homology, Amino Acid
Kinase
Adenosine Diphosphate
Phosphotransferases (Alcohol Group Acceptor)
chemistry
Biochemistry
biology.protein
Schizosaccharomyces pombe Proteins
Crystallization
Protein Binding
Subjects
Details
- ISSN :
- 00222836
- Volume :
- 326
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- Journal of molecular biology
- Accession number :
- edsair.doi.dedup.....b7c0530b2e81ad4560d430c455c20866