title: Sequence of the Clostridium thermocellum mannanase gene man26B and characterization of the translated product.
abstract: The man26B gene of Clostridium thermocellum strain F1 was found in pKS305, which had been selected as a recombinant plasmid conferring endoglucanase activity on Escherichia coli. The open reading frame of man26B consists of 1,773 nucleotides encoding a protein of 591 amino acids with a predicted molecular weight of 67,047. Man26B is a modular enzyme composed of an N-terminal signal peptide and three domains in the following order: a mannan-binding domain, a family 26 mannanase domain, and a dockerin domain responsible for cellulosome assembly. We found that this gene was a homologue of the man26A gene of C. thermocellum strain YS but that there were insertion or deletion mutations that caused a frame-shift mutation affecting a stretch of 26 amino acids in the catalytic domain. Man26B devoid of the dockerin domain was constructed and purified from a recombinant E. coli, and its enzyme properties were examined. Immunological analysis indicated that Man26B was a catalytic component of the C. thermocellum F1 cellulosome.
authors.affiliation: Faculty of Bioresources, Mie University, Tsu, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Kurokawa
authors.forename: E
authors.initials: E
authors.lastname: Hemjinda
authors.forename: T
authors.initials: T
authors.lastname: Arai
authors.forename: S
authors.initials: S
authors.lastname: Karita
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: K
authors.initials: K
authors.lastname: Sakka
authors.forename: K
authors.initials: K
authors.lastname: Ohmiya
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003013:Clostridium / Q000201:enzymology* / Q000235:genetics; D004269:DNA, Bacterial; D005798:Genes, Bacterial; D008361:Mannosidases / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D044902:beta-Mannosidase
chemical_list: D004269:DNA, Bacterial; D008361:Mannosidases; D044902:beta-Mannosidase; C041867:endo-1,4-beta-D-mannanase