title: Identification of an N-terminal formylated, two-peptide bacteriocin from Enterococcus faecalis 710C.
abstract: Enterococcus faecalis 710C, isolated from beef product, has a broad antimicrobial activity spectrum against foodborne pathogens. Two bacteriocins, enterocin 7A (Ent7A) and enterocin 7B (Ent7B), were purified from the culture supernatant of E. faecalis 710C and characterized using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and electrospray infusion tandem mass spectrometry analyses. These data and subsequent genetic analysis showed that Ent7A and Ent7B are produced without N-terminal leader sequences and have amino acid sequences that are identical to those of enterocins MR10A and MR10B, respectively. However, the observed masses for Ent7A and Ent7B are 5200.80 and 5206.65 Da (monoisotopic mass), respectively, which are higher than the theoretical molecular masses of MR10A and MR10B, respectively. This study provides evidence that both Ent7A and Ent7B are formylated on the N-terminal methionine residue. Purified Ent7A and Ent7B are active against spoilage microorganisms and foodborne pathogens, including Clostridium sporogenes , Listeria monocytogenes , and Staphylococcus aureus as well as Brevundimonas diminuta , which has been associated with infections among immune-suppressed cancer patients.
authors.affiliation: Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Xiaoji
authors.initials: X
authors.lastname: Liu
authors.forename: John C
authors.initials: JC
authors.lastname: Vederas
authors.forename: Randy M
authors.initials: RM
authors.lastname: Whittal
authors.forename: Jing
authors.initials: J
authors.lastname: Zheng
authors.forename: Michael E
authors.initials: ME
authors.lastname: Stiles
authors.forename: Denise
authors.initials: D
authors.lastname: Carlson
authors.forename: Charles M A P
authors.initials: CM
authors.lastname: Franz
authors.forename: Lynn M
authors.initials: LM
authors.lastname: McMullen
authors.forename: Marco J
authors.initials: MJ
authors.lastname: van Belkum
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D001430:Bacteriocins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D013293:Enterococcus faecalis / Q000737:chemistry*; D005516:Food Microbiology; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; C561324:enterocin 7A, Enterococcus faecalis; C561325:enterocin 7B, Enterococcus faecalis