Pathways & interactions
Bacteriocin, class IIa (IPR002633)
Short name: Bacteriocin_IIa
Many Gram-positive bacteria produce ribosomally synthesized antimicrobial peptides, often termed bacteriocins. One important and well studied class of bacteriocins is the class IIa or pediocin-like bacteriocins produced by lactic acid bacteria. All class IIa bacteriocins are produced by food-associated strains, isolated from a variety of food products of industrial and natural origins, including meat products, dairy products and vegetables. Class IIa bacteriocins are all cationic, display anti-Listeria activity, and kill target cells by permeabilizing the cell membrane [PMID: 16232543, PMID: 15611086, PMID: 16059970].
Class IIa bacteriocins contain between 37 and 48 residues. Based on their primary structures, the peptide chains of class IIa bacteriocins may be divided roughly into two regions: a hydrophilic, cationic and highly conserved N-terminal region, and a less conserved hydrophobic/amphiphilic C-terminal region. The N-terminal region contains the conserved Y-G-N-G-V/L 'pediocin box' motif and two conserved cysteine residues joined by a disulphide bridge. It forms a three-stranded antiparallel beta-sheet supported by the conserved disulphide bridge. This cationic N-terminal beta-sheet domain mediates binding of the class IIa bacteriocin to the target cell membrane. The C-terminal region forms a hairpin-like domain that penetrates into the hydrophobic part of the target cell membrane, thereby mediating leakage through the membrane. The two domains are joined by a hinge, which enables movement of the domains relative to each other [PMID: 15611086, PMID: 16059970].
Some proteins known to belong to the class IIa bacteriocin family are listed below:
- Pediococcus acidilactici pediocin PA-1.
- Leuconostoc mesenteroides mesentericin Y105.
- Carnobacterium piscicola carnobacteriocin B2.
- Lactobacillus sakei sakacin P.
- Enterococcus faecium (Streptococcus faecium) enterocin A.
- E. faecium enterocin P.
- Leuconostoc gelidum leucocin A.
- Lactobacillus curvatus curvacin A.
- Listeria innocua listeriocin 743A.