title: Crystal structure and site-directed mutagenesis of a nitroalkane oxidase from Streptomyces ansochromogenes.
abstract: Nitroalkane oxidase (NAO) catalyzes neutral nitroalkanes to their corresponding aldehydes or ketones, hydrogen peroxide and nitrite. The crystal structure of NAO from Streptomyces ansochromogenes was determined; it consists of two domains, a TIM barrel domain bound to FMN and C-terminal domain with a novel folding pattern. Site-directed mutagenesis of His179, which is spatially adjacent to FMN, resulted in the loss of enzyme activity, demonstrating that this amino acid residue is important for catalysis. The crystal structure of mutant H179D-nitroethane was also analyzed. Interestingly, Sa-NAO shows the typical function as nitroalkane oxidase but its structure is similar to that of 2-nitropropane dioxygenase. Overall, these results suggest that Sa-NAO is a novel nitroalkane oxidase with TIM barrel structure.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Li
authors.forename: Zengqiang
authors.initials: Z
authors.lastname: Gao
authors.forename: Haifeng
authors.initials: H
authors.lastname: Hou
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Jihui
authors.initials: J
authors.lastname: Zhang
authors.forename: Haihua
authors.initials: H
authors.lastname: Yang
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Dong
authors.forename: Huarong
authors.initials: H
authors.lastname: Tan
mesh_terms: D018360:Crystallography, X-Ray; D049308:Dioxygenases / Q000737:chemistry* / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013302:Streptomyces / Q000201:enzymology*
chemical_list: D049308:Dioxygenases; C021876:2-nitropropane dioxygenase