title: Characterization of an endo-beta-1,6-Galactanase from Streptomyces avermitilis NBRC14893.
abstract: The putative endo-beta-1,6-galactanase gene from Streptomyces avermitilis was cloned and expressed in Escherichia coli, and the enzymatic properties of the recombinant enzyme were characterized. The gene consisted of a 1,476-bp open reading frame and encoded a 491-amino-acid protein, comprising an N-terminal secretion signal sequence and glycoside hydrolase family 5 catalytic module. The recombinant enzyme, Sa1,6Gal5A, catalyzed the hydrolysis of beta-1,6-linked galactosyl linkages of oligosaccharides and polysaccharides. The enzyme produced galactose and a range of beta-1,6-linked galacto-oligosaccharides, predominantly beta-1,6-galactobiose, from beta-1,6-galactan chains. There was a synergistic effect between the enzyme and Sa1,3Gal43A in degrading tomato arabinogalactan proteins. These results suggest that Sa1,6Gal5A is the first identified endo-beta-1,6-galactanase from a prokaryote.
authors.affiliation: National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Ichinose
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Kotake
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Tsumuraya
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kaneko
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005656:Fungal Proteins; D005685:Galactans / Q000494:pharmacology; D005690:Galactose / Q000378:metabolism; D015870:Gene Expression; D006026:Glycoside Hydrolases / Q000235:genetics; D007700:Kinetics; D018551:Solanum lycopersicum; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000378:metabolism; D016366:Open Reading Frames; D010940:Plant Proteins / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D021382:Protein Sorting Signals; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics; D013379:Substrate Specificity; D001616:beta-Galactosidase / Q000235:genetics* / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D005656:Fungal Proteins; D005685:Galactans; D009844:Oligosaccharides; D010940:Plant Proteins; D011134:Polysaccharides; D021382:Protein Sorting Signals; D011994:Recombinant Proteins; D006026:Glycoside Hydrolases; C478178:endo-beta-(1-6)-galactanase; D001616:beta-Galactosidase; C005653:arabinogalactan; D005690:Galactose