Bacteriocin: Plantaricin W β

Bacteriocin: Plantaricin W β

Accession: BAC114

Class: Lantibiotic (two-peptide)

Gene: PlwâA

Producer Organism: Lactobacillus plantarum [Gram-positive]

Taxonomy: BacteriaFirmicutesLactobacillalesLactobacillaceaeLactobacillus

Target organismsLactobacillus spp - Lactobacillus lactis - Oenococcus oeni - Leuconostoc mesenteroides - Pediococcus acidilactici - Pediococcus pentosaceus - Enterococcus faecalis - Listeria innocua - Listeria monocytogenes - Propionibacterium freudenreichii - Staphylococcus aureus

Mode of action:
Plantaricin W (Plw) is a new two-peptide bacteriocin, from Lactobacillus plantarum, which inhibits a large number of Gram-positive bacteria. The two individual peptides, Plwa (comprising 29 residues) and Plwb (comprising 32 residues), had low antimicrobial activity but acted synergistically. The data indicate that the two peptides work in a 1:1 ratio. Chemical analyses showed that both peptides are lantibiotics, but two unmodified cysteines and one serine residue were present in Plwa, and Plwb contained one cysteine residue.

The Plw structural genes were sequenced and shown to encode prepeptides with sequence similarities to two other two-peptide lantibiotics, namely staphylococcin C55 and lacticin 3147.

The conserved residues are mainly serines, threonines and cysteines that can be involved in intramolecular thioether bond formation in the C-terminal parts of the molecules.

Post-translational modification:
Plwb is synthesized with a 29 aa leader, processed by an ABC transporter and then subjected to further proteolytic attack, resulting in the removal of the six Nterminal residues.