Biochemical and molecular characterization of a levansucrase from Lactobacillus reuteri
| Autor: | Ewa Szalowska, van der Marc Maarel, S.A F T van Hijum, Lubbert Dijkhuizen |
|---|---|
| Přispěvatelé: | Groningen Biomolecular Sciences and Biotechnology, GBB Microbiology Cluster, Host-Microbe Interactions, Faculty of Science and Engineering |
| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
DNA
Bacterial STRAIN Molecular Sequence Data Inulin LACTIC-ACID BACTERIA Microbiology chemistry.chemical_compound Fructan LEUCONOSTOC-CITREUM Carbohydrate Conformation Escherichia coli INULOSUCRASE Amino Acid Sequence Raffinose Sequence Deletion SALIVARIUS ATCC 25975 Inulosucrase Base Sequence Sequence Homology Amino Acid biology Levansucrase Fructose ENZYMATIC-PROPERTIES biology.organism_classification STREPTOCOCCUS-MUTANS Recombinant Proteins LIGHT-SCATTERING Fructans Lactobacillus reuteri Kinetics Lactobacillus Streptococcus salivarius FRUCTOSYLTRANSFERASE Hexosyltransferases chemistry Biochemistry Genes Bacterial INULIN |
| Zdroj: | Microbiology, 150(3), 621-630. MAIK NAUKA/INTERPERIODICA/SPRINGER Scopus-Elsevier |
| ISSN: | 1465-2080 1350-0872 |
| Popis: | Lactobacillus reuteri strain 121 employs a fructosyltransferase (FTF) to synthesize a fructose polymer [a fructan of the levan type, with β(2→6) linkages] from sucrose or raffinose. Purification of this FTF (a levansucrase), and identification of peptide amino acid sequences, allowed isolation of the first Lactobacillus levansucrase gene (lev), encoding a protein (Lev) consisting of 804 amino acids. Lev showed highest similarity with an inulosucrase of L. reuteri 121 [Inu; producing an inulin polymer with β(2→1)-linked fructosyl units] and with FTFs from streptococci. Expression of lev in Escherichia coli resulted in an active FTF (LevΔ773His) that produced the same levan polymer [with only 2-3 % β(2→1→6) branching points] as L. reuteri 121 cells grown on raffinose. The low degree of branching of the L. reuteri levan is very different from bacterial levans known up to now, such as that of Streptococcus salivarius, having up to 30 % branches. Although Lev is unusual in showing a higher hydrolysis than transferase activity, significant amounts of levan polymer are produced both in vivo and in vitro. Lev is strongly dependent on Ca2+ ions for activity. Unique properties of L. reuteri Lev together with Inu are: (i) the presence of a C-terminal cell-wall-anchoring motif causing similar expression problems in Escherichia coli, (ii) a relatively high optimum temperature for activity for FTF enzymes, and (iii) at 50 °C, kinetics that are best described by the Hill equation. © 2004 SGM. Chemicals / CAS: amino acid, 65072-01-7; calcium ion, 14127-61-8; fructose, 30237-26-4, 57-48-7, 7660-25-5, 77907-44-9; inulin, 9005-80-5; levan, 50815-13-9, 9013-95-0; levansucrase, 9030-17-5; raffinose, 512-69-6; sucrose, 122880-25-5, 57-50-1; transferase, 9047-61-4; DNA, Bacterial; Fructans; Hexosyltransferases, EC 2.4.1.-; levansucrase, EC 2.4.1.10; Recombinant Proteins. Molecular Sequence Numbers: GENBANK: AF459437, AL162757, CAA05973, L08445, M18954, P11701, Q06447, Q55242, X02730, AF465251 |
| Databáze: | OpenAIRE |
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