title: Structural and mechanistic studies on ThiO, a glycine oxidase essential for thiamin biosynthesis in Bacillus subtilis.
abstract: The thiO gene of Bacillus subtilis encodes an FAD-dependent glycine oxidase. This enzyme is a homotetramer with a monomer molecular mass of 42 kDa. In this paper, we demonstrate that ThiO is required for the biosynthesis of the thiazole moiety of thiamin pyrophosphate and describe the structure of the enzyme with N-acetylglycine bound at the active site. The closest structural relatives of ThiO are sarcosine oxidase and d-amino acid oxidase. The ThiO structure, as well as the observation that N-cyclopropylglycine is a good substrate, supports a hydride transfer mechanism for the enzyme. A mechanistic proposal for the role of ThiO in thiazole biosynthesis is also described.
authors.affiliation: Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Ethan C
authors.initials: EC
authors.lastname: Settembre
authors.forename: Pieter C
authors.initials: PC
authors.lastname: Dorrestein
authors.forename: Joo-Heon
authors.initials: JH
authors.lastname: Park
authors.forename: Amy M
authors.initials: AM
authors.lastname: Augustine
authors.forename: Tadhg P
authors.initials: TP
authors.lastname: Begley
authors.forename: Steven E
authors.initials: SE
authors.lastname: Ealick
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000737:chemistry* / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D003903:Deuterium / Q000737:chemistry; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry; D005415:Flavins / Q000737:chemistry; D005420:Flavoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D013237:Stereoisomerism; D013379:Substrate Specificity; D013831:Thiamine / Q000096:biosynthesis*; D013844:Thiazoles / Q000737:chemistry / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D005415:Flavins; D005420:Flavoproteins; D013844:Thiazoles; D005182:Flavin-Adenine Dinucleotide; D003903:Deuterium; D000594:Amino Acid Oxidoreductases; C115925:glycine oxidase; D013831:Thiamine