title: Solution structure of the Escherichia coli protein ydhR: a putative mono-oxygenase.
abstract: YdhR is a 101-residue conserved protein from Escherichia coli. Sequence searches reveal that the protein has >50% identity to proteins found in a variety of other bacterial genomes. Using size exclusion chromatography and fluorescence spectroscopy, we determined that ydhR exists in a dimeric state with a dissociation constant of approximately 40 nM. The three-dimensional structure of dimeric ydhR was determined using NMR spectroscopy. A total of 3400 unambiguous NOEs, both manually and automatically assigned, were used for the structure calculation that was refined using an explicit hydration shell. A family of 20 structures was obtained with a backbone RMSD of 0.48 A for elements of secondary structure. The structure reveals a dimeric alpha,beta fold characteristic of the alpha+beta barrel superfamily of proteins. Bioinformatic approaches were used to show that ydhR likely belongs to a recently identified group of mono-oxygenase proteins that includes ActVA-Orf6 and YgiN and are involved in the oxygenation of polyaromatic ring compounds.
authors.affiliation: Department of Biochemistry, The University of Western Ontario, London, ON, N6A 5C1, Canada.
authors.forename: Matthew
authors.initials: M
authors.lastname: Revington
authors.forename: Anthony
authors.initials: A
authors.lastname: Semesi
authors.forename: Adelinda
authors.initials: A
authors.lastname: Yee
authors.forename: Gary S
authors.initials: GS
authors.lastname: Shaw
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D029968:Escherichia coli Proteins; D006899:Mixed Function Oxygenases; C507444:ydhR protein, E coli