title: Active site architecture of a sugar N-oxygenase.
abstract: KijD3 is a flavin-dependent N-oxygenase implicated in the formation of the nitro-containing sugar d-kijanose, found attached to the antibiotic kijanimicin. For this investigation, the structure of KijD3 in complex with FMN and its dTDP-sugar substrate was solved to 2.1 Å resolution. In contrast to the apoenzyme structure, the C-terminus of the protein becomes ordered and projects into the active site cleft [Bruender, N. A., Thoden, J. B., and Holden, H. M. (2010) Biochemistry 49, 3517-3524]. The amino group of the dTDP-aminosugar that is oxidized is located 4.9 Å from C4a of the flavin ring. The model provides a molecular basis for understanding the manner in which KijD3 catalyzes its unusual chemical transformation.
authors.affiliation: Department of Biochemistry, University of Wisconsin , Madison, Wisconsin 53706, United States.
authors.forename: James B
authors.initials: JB
authors.lastname: Thoden
authors.forename: Megan C
authors.initials: MC
authors.lastname: Branch
authors.forename: Alex L
authors.initials: AL
authors.lastname: Zimmer
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Bruender
authors.forename: Hazel M
authors.initials: HM
authors.lastname: Holden
mesh_terms: D000192:Actinomycetales / Q000201:enzymology; D000606:Amino Sugars / Q000378:metabolism; D000617:Aminoglycosides / Q000378:metabolism; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D008024:Ligands; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D055672:Static Electricity
chemical_list: D000606:Amino Sugars; D000617:Aminoglycosides; D008024:Ligands; C033276:kijanimicin; D010105:Oxygenases