3.5.3
The Class IIA Bacteriocins Pediocin PA-1/AcH and Mesentericin Y105
Although the class IIA, anti-listerial bacteriocins pediocin PA-1/AcH and
mesentericin Y105, are produced by Pediococcus and Leuconostoc sp., respectively, they are nevertheless genetically organized in a way almost identical to
the lactococcal bacteriocins (Fig. 4) [124, 130, 131]. MesC, a 137-amino acid
protein upstream mesD in the mesentericin Y105 gene cluster shows no homology with known protein [124].
3.5.4
The Lactobacillus Bacteriocins Sakacin A and Plantaricin A
Axelsson et al. [147] (1993) shotgun cloned the plasmid fraction of L. sake
Lb706 directly in a sakacin A non-producing and sensitive variant L. sake
Lb706-B. One of the two clones, necessary for the restoration of immunity
encoded a 430-amino acid residue protein designated as SakB [147]. Hybridization and sequence analysis revealed that sakB complemented a mutated copy
of sakB present in L. sake Lb706-B. The gene mapped 1.6 kb from the structural
sakacin A gene on the 60-kb plasmid. Further investigation showed that SakB
was part of a two-component, bacterial signal transduction system, adjacent to
the sakacin A operon [133]. SakB was renamed SapK, and showed striking
homology to the Staphylococcus aureus AgrC histidine protein kinase (HPR). A
second member of the two-component signal transduction apparatus, SapR,
was encoded downstream from SapK. The SapR protein has homology to AgrA,
a member of the response regulator (RR) family [108, 133, 148].
A comparable signal transduction system was found to be encoded in the
same operon as the structural plantaricin A gene (plnA), and was transcribed as
a 3.3 kb plnABCD messenger [134]. PlnB, PlnC, and PlnD showed highest
homology to their counterparts in the agr (accessory gene regulatory) twocomponent regulatory system of Staphylococcus aureus [134, 149, 150]. PlnB
showed highest homology to the histidine protein kinase family and is predicted as an integral protein of the cytoplasmic membrane with six transmembrane domains located in its N-terminus [134]. PlnC and PlnD are very homologous and corresponded to the response regulator family protein of the
Staphylococcus aureus agr locus [134, 149, 150]. Additionally, recent findings
suggest that two bacteriocins of the two-peptide type (PlnJ and PlnK of the
plnJKLR operon and PlnE and PlnF of the plnEFI operon) and a bacteriocin of
the one-peptide type (PlnM of the plnMNOP operon) were located adjacent to
the plnABCD cluster and could hence be responsible for bacteriocin activity
[49]. PlnI (257 amino acids), PlnP (247 amino acids), and PlnL (138 amino
acids) encode hydrophobic proteins with three (PlnL) and seven (PlnI and
PlnP) transmembrane domains, respectively. In the case of PlnI and PlnL, these
proteins are encoded in the 3¢ end immediately downstream from the bacteriocin determinants, following the conserved genetic organization of all twocomponent bacteriocins described up to now [49, 77, 128, 136]. PlnP however, is
separated from the bacteriocin genes by plnO, an open reading frame of 399
34
E. Sablon et al.
The Class IIA Bacteriocins Pediocin PA-1/AcH and Mesentericin Y105
Although the class IIA, anti-listerial bacteriocins pediocin PA-1/AcH and
mesentericin Y105, are produced by Pediococcus and Leuconostoc sp., respectively, they are nevertheless genetically organized in a way almost identical to
the lactococcal bacteriocins (Fig. 4) [124, 130, 131]. MesC, a 137-amino acid
protein upstream mesD in the mesentericin Y105 gene cluster shows no homology with known protein [124].
3.5.4
The Lactobacillus Bacteriocins Sakacin A and Plantaricin A
Axelsson et al. [147] (1993) shotgun cloned the plasmid fraction of L. sake
Lb706 directly in a sakacin A non-producing and sensitive variant L. sake
Lb706-B. One of the two clones, necessary for the restoration of immunity
encoded a 430-amino acid residue protein designated as SakB [147]. Hybridization and sequence analysis revealed that sakB complemented a mutated copy
of sakB present in L. sake Lb706-B. The gene mapped 1.6 kb from the structural
sakacin A gene on the 60-kb plasmid. Further investigation showed that SakB
was part of a two-component, bacterial signal transduction system, adjacent to
the sakacin A operon [133]. SakB was renamed SapK, and showed striking
homology to the Staphylococcus aureus AgrC histidine protein kinase (HPR). A
second member of the two-component signal transduction apparatus, SapR,
was encoded downstream from SapK. The SapR protein has homology to AgrA,
a member of the response regulator (RR) family [108, 133, 148].
A comparable signal transduction system was found to be encoded in the
same operon as the structural plantaricin A gene (plnA), and was transcribed as
a 3.3 kb plnABCD messenger [134]. PlnB, PlnC, and PlnD showed highest
homology to their counterparts in the agr (accessory gene regulatory) twocomponent regulatory system of Staphylococcus aureus [134, 149, 150]. PlnB
showed highest homology to the histidine protein kinase family and is predicted as an integral protein of the cytoplasmic membrane with six transmembrane domains located in its N-terminus [134]. PlnC and PlnD are very homologous and corresponded to the response regulator family protein of the
Staphylococcus aureus agr locus [134, 149, 150]. Additionally, recent findings
suggest that two bacteriocins of the two-peptide type (PlnJ and PlnK of the
plnJKLR operon and PlnE and PlnF of the plnEFI operon) and a bacteriocin of
the one-peptide type (PlnM of the plnMNOP operon) were located adjacent to
the plnABCD cluster and could hence be responsible for bacteriocin activity
[49]. PlnI (257 amino acids), PlnP (247 amino acids), and PlnL (138 amino
acids) encode hydrophobic proteins with three (PlnL) and seven (PlnI and
PlnP) transmembrane domains, respectively. In the case of PlnI and PlnL, these
proteins are encoded in the 3¢ end immediately downstream from the bacteriocin determinants, following the conserved genetic organization of all twocomponent bacteriocins described up to now [49, 77, 128, 136]. PlnP however, is
separated from the bacteriocin genes by plnO, an open reading frame of 399
34
E. Sablon et al.