title: Overview of the glucansucrase equipment of Leuconostoc citreum LBAE-E16 and LBAE-C11, two strains isolated from sourdough.
abstract: The whole set of putative glucansucrases from Leuconostoc citreum LBAE-E16 and LBAE-C11 was retrieved from the draft genome sequence of these two sourdough strains previously suggested as alternan producers. Four and five putative glycoside hydrolase family 70 (GH70) encoding genes were identified in the genome sequence of strain C11 and E16, respectively. Some putative genes have high sequence identity to known Leuconostoc dextransucrases. Molecular and biochemical data confirmed that L. citreum C11 could be considered as a new alternan-producing strain, unlike strain E16. In the latter, two new putative glucansucrases with unusual structural features were retrieved. In particular, the GSE16-5 gene encodes for a protein of 2063 amino acids with a theoretical molecular mass of 229 kDa that shares 61% identity with the alternansucrase (ASR) of L. citreum NRRL B-1355, due to the presence of seven APY repeats identified in the C-terminal peptide sequence. Cloning and expression of the corresponding coding sequence revealed synthesis of a low molecular weight (10(4) Da) linear dextran polymer with glucosyl residues only linked by α-1,6 linkages. This novel GH70 enzyme may thus be viewed as a natural chimeric enzyme resulting from the addition of the ASR C-terminal region in a dextransucrase.
authors: Université de Toulouse; Laboratoire de Biotechnologies Agroalimentaire et Environnementale, EA 4565, Institut Universitaire de Technologie, Université Paul Sabatier, 24, Rue d'Embaquès, F-32000 Auch, France.
authors: Myriam
authors: M
authors: Amari
authors: Université de Toulouse; Laboratoire de Biotechnologies Agroalimentaire et Environnementale, EA 4565, Institut Universitaire de Technologie, Université Paul Sabatier, 24, Rue d'Embaquès, F-32000 Auch, France.
authors: Gabriel
authors: G
authors: Valérie
authors: Université de Toulouse; Laboratoire de Biotechnologies Agroalimentaire et Environnementale, EA 4565, Institut Universitaire de Technologie, Université Paul Sabatier, 24, Rue d'Embaquès, F-32000 Auch, France.
authors: Hervé
authors: H
authors: Robert
authors: Université de Toulouse; INSA, UPS, INP, LISBP, 135 avenue de Rangueil, F-31077 Toulouse, France INRA, UMR792, Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France CNRS, UMR5504, F-31400 Toulouse, France.
authors: Sandrine
authors: S
authors: Morel
authors: Université de Toulouse; INSA, UPS, INP, LISBP, 135 avenue de Rangueil, F-31077 Toulouse, France INRA, UMR792, Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France CNRS, UMR5504, F-31400 Toulouse, France.
authors: Claire
authors: C
authors: Moulis
authors: Université de Toulouse; Laboratoire de Biotechnologies Agroalimentaire et Environnementale, EA 4565, Institut Universitaire de Technologie, Université Paul Sabatier, 24, Rue d'Embaquès, F-32000 Auch, France.
authors: Bruno
authors: B
authors: Gabriel
authors: Université de Toulouse; INSA, UPS, INP, LISBP, 135 avenue de Rangueil, F-31077 Toulouse, France INRA, UMR792, Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France CNRS, UMR5504, F-31400 Toulouse, France.
authors: Magali
authors: M
authors: Remaud-Siméon
authors: Université de Toulouse; Laboratoire de Biotechnologies Agroalimentaire et Environnementale, EA 4565, Institut Universitaire de Technologie, Université Paul Sabatier, 24, Rue d'Embaquès, F-32000 Auch, France cathy.faucher@iut-tlse3.fr.
authors: Catherine
authors: C
authors: Fontagné-Faucher
mesh_terms: D020816:Amino Acid Motifs; D003001:Cloning, Molecular; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D003911:Dextrans / Q000378:metabolism*; D019143:Evolution, Molecular; D005516:Food Microbiology; D015870:Gene Expression; D016680:Genome, Bacterial; D005936:Glucans / Q000378:metabolism*; D016695:Glycosyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D007934:Leuconostoc / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
chemical_list: D004269:DNA, Bacterial; D003911:Dextrans; D005936:Glucans; C439358:alternan; D016695:Glycosyltransferases; C033837:alternansucrase
keywords: APY repeats; L. citreum; alternansucrase; dextransucrase; glucansucrase