Title: | The synthesis of the bacteriocin sakacin A is a temperature-sensitive process regulated by a pheromone peptide through a three-component regulatory system |
Author(s): | Diep DB; Axelsson L; Grefsli C; Nes IF; |
Address: | "Laboratory for Microbial Gene Technology, Department of Biotechnological Sciences, Agricultural University of Norway, PO Box 5051,N-1432 As, Norway1. MATFORSK, Norwegian Food Research Institute, Osloveien 1, N-1430 As, Norway2" |
DOI: | 10.1099/00221287-146-9-2155 |
ISSN/ISBN: | 1350-0872 (Print) 1350-0872 (Linking) |
Abstract: | "Sakacin A is a bacteriocin produced by Lactobacillus sakei Lb706. The gene cluster (sap) encompasses a regulatory unit composed of three consecutive genes, orf4 and sapKR. sapKR encode a histidine protein kinase and a response regulator, while orf4 encodes the putative precursor of a 23-amino-acid cationic peptide (termed Sap-Ph). The authors show that Sap-Ph serves as a pheromone regulating bacteriocin production. Lb706 produced bacteriocin when the growth temperature was kept at 25 or 30 degrees C, but production was reduced or absent at higher temperatures (33.5-35 degrees C). Production was restored by lowering the growth temperature to 30 degrees C, but at temperatures of 33-34 degrees C also by adding exogenous Sap-Ph to the growth medium. A knock-out mutation in orf4 abolished sakacin A production. Exogenously added Sap-Ph complemented this mutation, unambiguously showing the essential role of this peptide for bacteriocin production. Another sakacin A producer, Lactobacillus curvatus LTH1174, had a similar response to temperature and exogenously added Sap-Ph" |
Keywords: | "Amino Acid Sequence Bacteriocins/*biosynthesis/*genetics Base Sequence *Gene Expression Regulation, Bacterial Genes, Bacterial Histidine Kinase Lactobacillus/*drug effects/genetics/growth & development/metabolism Molecular Sequence Data Multigene Family O;" |
Notes: | "MedlineDiep, Dzung B Axelsson, Lars Grefsli, Camilla Nes, Ingolf F eng Research Support, Non-U.S. Gov't England 2000/09/07 Microbiology (Reading). 2000 Sep; 146 ( Pt 9):2155-2160. doi: 10.1099/00221287-146-9-2155" |