title: Molecular cloning of the gene for 2,6-beta-D-fructan 6-levanbiohydrolase from Streptomyces exfoliatus F3-2.
abstract: The gene encoding a 2,6-beta-D-fructan 6-levanbiohydrolase (LF2ase) (EC 3.2.1.64) that converts levan into levanbiose was cloned from the genomic DNA of Streptomyces exfoliatus F3-2. The gene encoded a signal peptide of 37 amino acids and a mature protein of 482 amino acids with a total length of 1560 bp and was successfully expressed in Escherichia coli. The similarities of primary structure were observed with levanases from Clostridium acetobutylicum, Bacillus subtilis, B. stearothermophilus (51.0-54.3%) and with LF2ase from Microbacterium levaniformans (53.9%). The enzyme from S. exfoliatus F3-2 shared the conserved six domains and the completely conserved five amino acid residues with family 32 glycosyl hydrolases, which include levanase, inulinase, and invertase. These observations led to the conclusion that the enzyme belongs to family 32 glycosyl hydrolases.
authors.affiliation: Department of Upland Agriculture Research, National Agricultural Research Center for Hokkaido Region, Shinsei, Memuro, Kasai, 082-0071, Hokkaido, Japan. k.saito@affrc.go.jp
authors.forename: Katsuichi
authors.initials: K
authors.lastname: Saito
authors.forename: Yuji
authors.initials: Y
authors.lastname: Oda
authors.forename: Fusao
authors.initials: F
authors.lastname: Tomita
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yokota
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D006026:Glycoside Hydrolases / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D013302:Streptomyces / Q000145:classification / Q000201:enzymology* / Q000235:genetics
chemical_list: D017931:DNA Primers; D006026:Glycoside Hydrolases; C403663:2,6-beta-fructan 6-levanbiohydrolase