title: Cloning and characterization of an exoinulinase from Bacillus polymyxa.
abstract: A gene encoding an exoinulinase (inu) from Bacillus polymyxa MGL21 was cloned and sequenced. It is composed of 1455 nucleotides, encoding a protein (485 amino acids) with a molecular mass of 55,522 Da. Inu was expressed in Escherichia coli and the His-tagged exoinulinase was purified. The purified enzyme hydrolyzed sucrose, levan and raffinose, in addition to inulin, with a sucrose/inulin ratio of 2. Inulinase activity was optimal at 35 degrees C and pH 7, was completely inactivated by 1 mM Ag+ or Hg2+. The Km and Vmax values for inulin hydrolysis were 0.7 mM and 2500 microM min(-1) mg(-1) protein. The enzyme acted on inulin via an exo-attack to produce fructose mainly.
authors.affiliation: Mitsubishi Kagaku Institute of Life Sciences, Tokyo 194-8511, Japan.
authors.forename: Hyun-Ju
authors.initials: HJ
authors.lastname: Kwon
authors.forename: Sung-Jong
authors.initials: SJ
authors.lastname: Jeon
authors.forename: Dong-Ju
authors.initials: DJ
authors.lastname: You
authors.forename: Kwang-Hyeon
authors.initials: KH
authors.lastname: Kim
authors.forename: Yong-Kee
authors.initials: YK
authors.lastname: Jeong
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Kim
authors.forename: Young-Man
authors.initials: YM
authors.lastname: Kim
authors.forename: Byung-Woo
authors.initials: BW
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D003001:Cloning, Molecular; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005632:Fructose / Q000096:biosynthesis; D006026:Glycoside Hydrolases / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D007444:Inulin / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D012988:Soil Microbiology; D013045:Species Specificity; D013379:Substrate Specificity; D043324:beta-Fructofuranosidase
chemical_list: D011994:Recombinant Proteins; D005632:Fructose; D007444:Inulin; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase