3.3
Genetic Organization of the Sucrose-Nisin Transposon TN5276
The nisin gene cluster nisABTCIPRKFEG of approximately 15 kb includes
eleven different genes (Fig. 3) [40, 91, 92, 95, 96, 100–103]. Except for nisK, all
other genes were essential for nisin production or immunity [92, 101, 103, 104].
The structural nisA and the nisI gene were shown to be both necessary for
producer strain immunity [92]. The nisP gene encodes a subtilisin-like serine
protease [101], whereas the nisB and nisC genes are very conserved in other
lantibiotic operons and therefore very likely to encode proteins involved in the
post-translational modification reactions of lantibiotics [40]. NisT belongs to
the ABC family of exporter proteins, involved in ATP-dependent secretion [105,
106]. The proteins corresponding to the nisR and nisK genes, display homology
to the well-known two-component signal transduction regulator and sensorkinase proteins [101, 107, 108].
The nisFEG gene cluster downstream from nisABTCIPRK appeared to be
involved in immunity to nisin besides the nisA and nisI gene products [104].
NisI-NisF is homologous to an ABC transporter of Bacillus subtilis and the
MbcF-MbcE transporter of E. coli, which are involved in subtilin and microcin
B17 immunity, respectively [104, 109, 110]. NisG displays homology with preAntimicrobial Peptides of Lactic Acid Bacteria: Mode of Action, Genetics and Biosynthesis
29
Fig. 3. Representative lantibiotic gene clusters. A representative of the class IA I leader
peptides included in this figure is nisin [40, 92, 103, 104, 107]. A representative of the class
IA II lantibiotics included in this figure is lactococcin DR (lacticin 481) [118]. The lactocin S
leader does not follow the class IA I or the class IA II rules and might therefore represent a new
maturation pathway [40, 82]. The structural genes are highlighted as black arrowheads. Genes
with similar proposed function or substantial sequence similarity are highlighted in the same
manner. The number of amino acids encoded by each gene is indicated below the arrowheads, which indicate the direction of transcription. The function of several genes in the
lactocin S gene cluster is unknown (lasN, lasU, lasV, lasW and orf 57). The suffix A is used to
indicate the structural genes, the suffix T is used for ABC transporters, and the suffixes B, C
and M indicate the potential modification enzymes. NisI is the nisin immunity protein, MsR
and NisK constitute the two-component signal transduction system, and NisFEG forms a
heteromer involved in nisin immunity as an ABC exporter
Genetic Organization of the Sucrose-Nisin Transposon TN5276
The nisin gene cluster nisABTCIPRKFEG of approximately 15 kb includes
eleven different genes (Fig. 3) [40, 91, 92, 95, 96, 100–103]. Except for nisK, all
other genes were essential for nisin production or immunity [92, 101, 103, 104].
The structural nisA and the nisI gene were shown to be both necessary for
producer strain immunity [92]. The nisP gene encodes a subtilisin-like serine
protease [101], whereas the nisB and nisC genes are very conserved in other
lantibiotic operons and therefore very likely to encode proteins involved in the
post-translational modification reactions of lantibiotics [40]. NisT belongs to
the ABC family of exporter proteins, involved in ATP-dependent secretion [105,
106]. The proteins corresponding to the nisR and nisK genes, display homology
to the well-known two-component signal transduction regulator and sensorkinase proteins [101, 107, 108].
The nisFEG gene cluster downstream from nisABTCIPRK appeared to be
involved in immunity to nisin besides the nisA and nisI gene products [104].
NisI-NisF is homologous to an ABC transporter of Bacillus subtilis and the
MbcF-MbcE transporter of E. coli, which are involved in subtilin and microcin
B17 immunity, respectively [104, 109, 110]. NisG displays homology with preAntimicrobial Peptides of Lactic Acid Bacteria: Mode of Action, Genetics and Biosynthesis
29
Fig. 3. Representative lantibiotic gene clusters. A representative of the class IA I leader
peptides included in this figure is nisin [40, 92, 103, 104, 107]. A representative of the class
IA II lantibiotics included in this figure is lactococcin DR (lacticin 481) [118]. The lactocin S
leader does not follow the class IA I or the class IA II rules and might therefore represent a new
maturation pathway [40, 82]. The structural genes are highlighted as black arrowheads. Genes
with similar proposed function or substantial sequence similarity are highlighted in the same
manner. The number of amino acids encoded by each gene is indicated below the arrowheads, which indicate the direction of transcription. The function of several genes in the
lactocin S gene cluster is unknown (lasN, lasU, lasV, lasW and orf 57). The suffix A is used to
indicate the structural genes, the suffix T is used for ABC transporters, and the suffixes B, C
and M indicate the potential modification enzymes. NisI is the nisin immunity protein, MsR
and NisK constitute the two-component signal transduction system, and NisFEG forms a
heteromer involved in nisin immunity as an ABC exporter