title: Cyclic tetrasaccharide-synthesizing enzymes from Arthrobacter globiformis A19.
abstract: A bacterial strain Arthrobacter globiformis A19 producing cyclic tetrasaccharide (CTS) was isolated from soil. The enzymes, 6-alpha-glucosyltransferase (6GT) and 3-alpha-isomaltosyltransferase (IMT), involved in the synthesis of CTS were purified to homogeneity. The molecular and enzymatic properties of IMT from A. globiformis were similar to those of enzymes from Bacillus globisporus C11 and N75. Arthrobacter 6GT had a smaller molecular mass of 108 kDa and a higher optimum pH of 8.4 than the enzymes from strains of B. globisporus. The genes for IMT (ctsY) and 6GT (ctsZ) were cloned from the genome of A. globiformis A19. The two genes linked together in tandem and formed a gene cluster, ctsYZ. Both of the gene products showed similarities to alpha-glucosidases belonging to glycoside hydrolase family 31, and conserved two aspartic acids corresponding to the putative catalytic residues of the family enzymes. The enzymatic system for the production of CTS consisting of 6GT and IMT might be widespread among bacteria.
authors.affiliation: Amase Institute, Hayashibara Biochemical Laboratories, Inc., 7-7 Amase Minami-machi, Okayama 700-0834, Japan. amaseken@hayashibara.co.jp
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Mukai
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Maruta
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Satouchi
authors.forename: Michio
authors.initials: M
authors.lastname: Kubota
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Fukuda
authors.forename: Masashi
authors.initials: M
authors.lastname: Kurimoto
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tsujisaka
mesh_terms: D000595:Amino Acid Sequence; D001173:Arthrobacter / Q000201:enzymology* / Q000302:isolation & purification; D020134:Catalytic Domain; D003001:Cloning, Molecular; D005964:Glucosyltransferases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D009844:Oligosaccharides / Q000096:biosynthesis*; D016415:Sequence Alignment; D012988:Soil Microbiology
chemical_list: D009844:Oligosaccharides; D005964:Glucosyltransferases; C436710:maltosyltransferase