title: The mobile flavin of 4-OH benzoate hydroxylase.
abstract: Para-hydroxybenzoate hydroxylase inserts oxygen into substrates by means of the labile intermediate, flavin C(4a)-hydroperoxide. This reaction requires transient isolation of the flavin and substrate from the bulk solvent. Previous crystal structures have revealed the position of the substrate para-hydroxybenzoate during oxygenation but not how it enters the active site. In this study, enzyme structures with the flavin ring displaced relative to the protein were determined, and it was established that these or similar flavin conformations also occur in solution. Movement of the flavin appears to be essential for the translocation of substrates and products into the solvent-shielded active site during catalysis.
authors.affiliation: Department of Biological Chemistry, University of Michigan, Ann Arbor 48109.
authors.forename: D L
authors.initials: DL
authors.lastname: Gatti
authors.forename: B A
authors.initials: BA
authors.lastname: Palfey
authors.forename: M S
authors.initials: MS
authors.lastname: Lah
authors.forename: B
authors.initials: B
authors.lastname: Entsch
authors.forename: V
authors.initials: V
authors.lastname: Massey
authors.forename: D P
authors.initials: DP
authors.lastname: Ballou
authors.forename: M L
authors.initials: ML
authors.lastname: Ludwig
mesh_terms: D050565:Benzoate 4-Monooxygenase; D001665:Binding Sites; D002384:Catalysis; D003196:Computer Graphics; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry / Q000378:metabolism; D005415:Flavins / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D006899:Mixed Function Oxygenases / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010226:Parabens / Q000378:metabolism; D011487:Protein Conformation
chemical_list: D005415:Flavins; D010226:Parabens; D005182:Flavin-Adenine Dinucleotide; D006899:Mixed Function Oxygenases; D050565:Benzoate 4-Monooxygenase; C038193:4-hydroxybenzoic acid