title: Heterologous expression and functional characterization of a novel chitinase from the chitinolytic bacterium Chitiniphilus shinanonensis.
abstract: Chitiniphilus shinanonensis strain SAY3(T) is a chitinolytic bacterium isolated from moat water of Ueda Castle in Nagano Prefecture, Japan. Fifteen genes encoding putative chitinolytic enzymes (chiA-chiO) have been isolated from this bacterium. Five of these constitute a single operon (chiCDEFG). The open reading frames of chiC, chiD, chiE, and chiG show sequence similarity to family 18 chitinases, while chiF encodes a polypeptide with two chitin-binding domains but no catalytic domain. Each of the five genes was successfully expressed in Escherichia coli, and the resulting recombinant proteins were characterized. Four of the recombinant proteins (ChiC, ChiD, ChiE, and ChiG) exhibited endo-type chitinase activity toward chitinous substrates, while ChiF showed no chitinolytic activity. In contrast to most endo-type chitinases, which mainly produce a dimer of N-acetyl-D-glucosamine (GlcNAc) as final product, ChiG completely split the GlcNAc dimer into GlcNAc monomers, indicating that it is a novel chitinase.
authors.affiliation: Division of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano, Japan.
authors.forename: Lanxiang
authors.initials: L
authors.lastname: Huang
authors.forename: Arisa
authors.initials: A
authors.lastname: Shizume
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nogawa
authors.forename: Goro
authors.initials: G
authors.lastname: Taguchi
authors.forename: Makoto
authors.initials: M
authors.lastname: Shimosaka
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism; D000595:Amino Acid Sequence; D002686:Chitin / Q000378:metabolism*; D002688:Chitinases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D008969:Molecular Sequence Data; D009346:Neisseriaceae / Q000201:enzymology* / Q000235:genetics*; D009876:Operon / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D002686:Chitin; D002688:Chitinases; D000117:Acetylglucosamine