title: Identification of a novel DFA I-producing inulin fructotransferase from Streptomyces davawensis.
abstract: In this work, a novel gene encoding DFA I-forming inulin fructotransferase (IFTase) from Streptomyces davawensis SK39.001 was cloned and expressed in Escherichia coli. The enzyme was purified, identified, and characterized. The results showed that this IFTase (DFA I-forming) is a trimer (molecular weight of 125KDa) consisting of three identical subunits (the molecular weight as assayed by SDS-PAGE was approximately 40KDa). At pH 5.5 and 40°C, the maximum specific activity (approximately 100Umg-1) was achieved. Moreover, the enzyme was stable up to 70°C. Kmand Vmaxwere 2.89±0.2mM and 1.94±0.9mMmin-1, respectively. For exploring putative active sites and probable catalytic mechanisms, homology modelling and molecular docking methods after site-directed mutagenesis were applied to IFTase (DFA I-forming). The results revealed that D183 and E194 were potential catalytic residues of the purified enzyme.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China.
authors.forename: Shuhuai
authors.initials: S
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China.
authors.forename: Danyang
authors.initials: D
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan Universtiy, Wuxi, Jiangsu, 214122, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan Universtiy, Wuxi, Jiangsu, 214122, China. Electronic address: wmmu@jiangnan.edu.cn.
authors.forename: Wanmeng
authors.initials: W
authors.lastname: Mu
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020134:Catalytic Domain; D003001:Cloning, Molecular; D004187:Disaccharides / Q000096:biosynthesis / Q000737:chemistry*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006602:Hexosyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007444:Inulin / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013302:Streptomyces / Q000737:chemistry* / Q000201:enzymology; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D004187:Disaccharides; D011994:Recombinant Proteins; C036365:difructose anhydride I; D007444:Inulin; D006602:Hexosyltransferases; C097478:inulin fructotransferase (DFA I-producing)
keywords: Di-d-fructofuranose 1,2′:2,1′ dianhydride (DFA I); Homology modelling; Inulin; Inulin fructotransferase; Molecular docking