title: Crystal structure of oxidized flavodoxin, an essential protein in Helicobacter pylori.
abstract: The redox protein flavodoxin has been shown earlier to be reduced by the pyruvate-oxidoreductase (POR) enzyme complex of Helicobacter pylori, and also was proposed to be involved in the pathogenesis of gastric mucosa-associated lymphoid-tissue lymphoma (MALToma). Here, we report its X-ray structure, which is similar to flavodoxins of other bacteria and cyanobacteria. However, H. pylori flavodoxin has an alanine residue near the isoalloxazine ring of its cofactor flavin mononucleotide (FMN), while the other previously crystallized flavodoxins have a larger hydrophobic residue at this position. This creates a solute filled hole near the FMN cofactor of H. pylori flavodoxin. We also show that flavodoxin is essential for the survival of H. pylori, and conclude that its structure can be used as a starting point for the modeling of an inhibitor for the interaction between the POR-enzyme complex and flavodoxin.
authors.affiliation: Fachbereich Biologie, Universität Konstanz, D-78457 Konstanz, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Freigang
authors.forename: Kay
authors.initials: K
authors.lastname: Diederichs
authors.forename: Klaus P
authors.initials: KP
authors.lastname: Schäfer
authors.forename: Wolfram
authors.initials: W
authors.lastname: Welte
authors.forename: Ralf
authors.initials: R
authors.lastname: Paul
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D015139:Blotting, Southern; D003460:Crystallization; D018360:Crystallography, X-Ray; D017931:DNA Primers / Q000737:chemistry; D005486:Flavin Mononucleotide / Q000737:chemistry; D005418:Flavodoxin / Q000737:chemistry*; D016480:Helicobacter pylori / Q000737:chemistry*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D011994:Recombinant Proteins; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D005418:Flavodoxin; D011994:Recombinant Proteins; D005486:Flavin Mononucleotide