Structure of the thiamine- and flavin-dependent enzyme pyruvate oxidase.
Pyruvate oxidase from Lactobacillus plantarum is a tetrameric enzyme that decarboxylates pyruvate, producing hydrogen peroxide and the energy-storage metabolite acetylphosphate. Structure determination at 2.1 angstroms showed that the cofactors thiamine pyrophosphate (TPP) and flavin adenine dinucleotide (FAD) are bound at the carboxyl termini of six-stranded parallel beta sheets. The pyrophosphate moiety of TPP is bound to a metal ion and to a beta alpha alpha beta unit corresponding to an established sequence fingerprint. The spatial arrangement of TPP and FAD suggests that the oxidation of the oxyethyl intermediate does not occur by hydride displacement but rather by a two-step transfer of two electrons.
Muller
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YA
Institut für Organische Chemie und Biochemie, Albert-Ludwigs-Universität, Freiburg, Germany.
Schulz
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GE
D000595:Amino Acid Sequence; D001665:Binding Sites; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003460:Crystallization; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism / Q000494:pharmacology*; D007778:Lactobacillus / Q000201:enzymology*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D015394:Molecular Structure; D017433:Protein Structure, Secondary; D011771:Pyruvate Oxidase / Q000737:chemistry* / Q000378:metabolism; D013835:Thiamine Pyrophosphate / Q000378:metabolism / Q000494:pharmacology*; D014961:X-Ray Diffraction
D046911:Macromolecular Substances; D005182:Flavin-Adenine Dinucleotide; D011771:Pyruvate Oxidase; D013835:Thiamine Pyrophosphate