title: Cyclopropane fatty acid synthase from Oenococcus oeni: expression in Lactococcus lactis subsp. cremoris and biochemical characterization.
abstract: Bacterial cyclopropane fatty acid synthases (CFA synthases) catalyze the transfer of a methyl group from S-adenosyl-L-methionine (AdoMet) to the double bond of a lipid chain, thereby forming a cyclopropane ring. CFAs contribute to resistance to acidity, dryness, and osmotic imbalance in many bacteria. This work describes the first biochemical characterization of a lactic acid bacterium CFA synthase. We have overexpressed Oenococcus oeni CFA synthase in E. coli in order to purify the enzyme. The optimum cyclopropanation activity was obtained at pH 5.6 and 35.8 °C. The high K(m) (AdoMet) value obtained (2.26 mM) demonstrates the low affinity of O. oeni enzyme toward the L. lactis subsp. cremoris unsaturated phospholipids. These results explain the partial complementation of the L. lactis subsp. cremoris cfa mutant by the O. oeni cfa gene and suggest a probable substrate specificity of the O. oeni enzyme. The current study reveals an essential hypothesis about the specificity of O. oeni CFA synthase which could play a key function in the acid tolerance mechanisms of this enological bacterium.
authors: Unité Mixte de Recherche Procédés Alimentaires et Microbiologiques (UMR A 02.102 AgroSup Dijon-Université de Bourgogne), Equipe Vin Aliment Microbiologie et Stress, Institut Universitaire de la Vigne et du Vin "Jules Guyot", Rue Claude Ladrey, Campus Universitaire Montmuzard, BP 27877, 21078, Dijon, France.
authors: Thi Mai Huong
authors: TM
authors: To
authors: Unité Mixte de Recherche Procédés Alimentaires et Microbiologiques (UMR A 02.102 AgroSup Dijon-Université de Bourgogne), Equipe Vin Aliment Microbiologie et Stress, Institut Universitaire de la Vigne et du Vin "Jules Guyot", Rue Claude Ladrey, Campus Universitaire Montmuzard, BP 27877, 21078, Dijon, France. cosette.grandvalet@u-bourgogne.fr.|Institut National Supérieur des Sciences Agronomiques de l'Alimentation et de l'Environnement, AgroSup Dijon, Site Epicure, 1 Esplanade Erasme, Campus Universitaire, 21000, Dijon, France. cosette.grandvalet@u-bourgogne.fr.
authors: Cosette
authors: C
authors: Grandvalet
authors: Unité Mixte de Recherche Procédés Alimentaires et Microbiologiques (UMR A 02.102 AgroSup Dijon-Université de Bourgogne), Equipe Vin Aliment Microbiologie et Stress, Institut Universitaire de la Vigne et du Vin "Jules Guyot", Rue Claude Ladrey, Campus Universitaire Montmuzard, BP 27877, 21078, Dijon, France.
authors: Hervé
authors: H
authors: Alexandre
authors: Unité Mixte de Recherche Procédés Alimentaires et Microbiologiques (UMR A 02.102 AgroSup Dijon-Université de Bourgogne), Equipe Vin Aliment Microbiologie et Stress, Institut Universitaire de la Vigne et du Vin "Jules Guyot", Rue Claude Ladrey, Campus Universitaire Montmuzard, BP 27877, 21078, Dijon, France.
authors: Raphaëlle
authors: R
authors: Tourdot-Maréchal
mesh_terms: D004926:Escherichia coli / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D013294:Lactococcus lactis / Q000201:enzymology / Q000235:genetics; D008780:Methyltransferases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D009154:Mutation; D056585:Oenococcus / Q000201:enzymology* / Q000235:genetics*; D010743:Phospholipids / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D005227:Fatty Acids; D010743:Phospholipids; D008780:Methyltransferases; C019964:cyclopropane synthetase
keywords: CFA synthase; Enzymatic activity; Heterologous complementation; Oenococcus oeni