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PubMed2002

Function of Lactococcus lactis nisin immunity genes nisI and nisFEG after coordinated expression in the surrogate host Bacillus subtilis.

Nisin-producing Lactococcus lactis strains show a high degree of resistance to the action of nisin, which is based upon expression of the self-protection (immunity) genes nisI, nisF, nisE, and nisG. Different combinations of nisin immunity genes were integrated into the chromosome of a nisin-sensitive Bacillus subtilis host strain under the control of an inducible promoter. For the recipient strain, the highest level of acquired nisin tolerance was achieved after coordinated expression of all four nisin immunity genes. But either the lipoprotein NisI or the ABC transporter-homologous system NisFEG, respectively, were also able to protect the Bacillus host cells. The acquired immunity was specific to nisin and provided no tolerance to subtilin, a closely related lantibiotic. Quantitative in vivo peptide release assays demonstrated that NisFEG diminished the quantity of cell-associated nisin, providing evidence that one role of NisFEG is to transport nisin from the membrane into the extracellular space. NisI solubilized from B. subtilis membrane vesicles and recombinant hexahistidine-tagged NisI from Escherichia coli interacted specifically with nisin and not with subtilin. This suggests a function of NisI as a nisin-intercepting protein.

ATP-Binding Cassette Transporters↗

PubMed1994

Nisin as a model food preservative.

Nisin is a ribosomally synthesized peptide that has broad-spectrum antibacterial activity, including activity against many bacteria that are food-spoilage pathogens. Nisin is produced as a fermentation product of a food-grade bacterium, and the safety and efficacy of nisin as a food preservative have resulted in its widespread use throughout the world, including the U.S. Nisin is a member of the class of antimicrobial substances known as lantibiotics, so called because they contain the unusual amino acid lanthionine. Lantibiotics, in general, have considerable promise as food preservatives, although only nisin has been sufficiently well characterized to be used for this purpose. As the number of known natural lantibiotics has increased and their useful characteristics have been explored, it has become desirable to synthesize structural analogs of nisin and other lantibiotics that do not occur naturally. The fact that lantibiotics are gene-encoded peptides synthesized by transcription and translation allows structural variants to be generated by mutagenesis. This review focuses on the progress that has been made in the construction and biological expression of genetically engineered nisin structural analogs. For example, a host-vector pair has been engineered that permits the construction of mutants of the structural gene for subtilin, which is a naturally occurring structural analog of nisin. The vector is designed in such a way that the mutant gene can be substituted for the natural subtilin gene in the chromosome of Bacillus subtilis, which in turn directs the transcription, translation, posttranslational modifications, and secretion of the mature form of the structural analog. Several structural analogs have been constructed, and their properties have provided insight into some of the structure-function relationships in lantibiotics, as well as their mechanism of antimicrobial action. These advances are assessed together with potential problems in the future development of nisin analogs as valuable new food preservatives.

Amino Acid Sequence↗

PubMed1973

Additional antibiotic inhibitors of peptidoglycan synthesis.

Diumycin, janiemycin, nisin, and subtilin inhibited peptidoglycan synthesis catalyzed by particulate enzyme systems from Bacillus stearothermophilus and Escherichia coli. All of these, except for nisin, also induced accumulation of the lipid intermediate in peptidoglycan synthesis. Concentrations required for 50% inhibition of peptidoglycan synthesis were less than 0.1 mug/ml for diumycin and in the range of 10 to 100 mug/ml for janiemycin, nisin, and subtilin in both organisms. The discrepancy between the extremely low concentration of diumycin required to inhibit the in vitro system from E. coli and the much higher concentration required to inhibit growth of the organism is noteworthy.

Anti-Bacterial Agents↗

PubMed1999

Lysinoalanine in food and in antimicrobial proteins.

Heat and alkali treatment of food proteins widely used in food processing results in the formation of crosslinked amino acids such as lysinoalanine, ornithinoalanine, lanthionine, and methyl-lanthionine and concurrent racemization of L-amino acid isomers to D-analogues. The mechanism of lysinoalanine formation is a two-step process: first, hydroxide ion-catalyzed elimination of cysteine and serine residues to a dehydroalanine intermediate; second, reaction of the double bond of dehydroalanine with the epsilon-NH2 group of lysine to form a lysinoalanine crosslink. The corresponding elimination-addition reaction of threonine produces methyl-dehydroalanine, which then reacts with the NH2 and SH groups to form methyl-lysinoalanine and methyl-lanthionine, respectively. The crosslinked amino acids lanthionine and methyl-lanthionine are formed by analogous nucleophilic addition reactions of the SH group of cysteine to dehydroalanine and methyl-dehydroalanine, respectively. Processing conditions that favor these transformations include high pH, temperature and exposure time. Factors which minimize lysinoalanine formation include the presence of SH-containing amino acids such as cysteine, N-acetyl-cysteine, and glutathione, dephosphorylation of O-phosphoryl esters, and acylation of epsilon-NH2 groups of lysine side chains. The presence of lysinoalanine residues along a protein chain decreases digestibility and nutritional quality in rodents but enhances nutritional quality in ruminants. Protein-bound and free lysinoalanines are reported to induce enlargement of nuclei of rat kidney cells. All of the mentioned dehydro and crosslinked amino acids also occur naturally in certain peptide and protein antibiotics. These include duramycin, cinnamycin, epidermin, subtilin and the widely used food preservative nisin. Mechanistic rationalizations are offered for the observed antimicrobial activities of these compounds in relation to their structures. The cited findings and new research to better define the chemistry and dietary and antimicrobial roles of lysinoalanine and related compounds should lead to better and safer foods.

Animals↗

PubMed1996

Structure-activity relationships in the peptide antibiotic nisin: antibacterial activity of fragments of nisin.

The post-translationally modified peptide antibiotic nisin has been cleaved by a number of proteases and the fragments produced purified, characterised chemically, and assayed for activity in inhibiting the growth of Lactococcus lactis MG1614 and Micrococcus luteus NCDO8166. These results provide information on the importance of different parts of the nisin molecule for its growth-inhibition activity. Removal of the C-terminal five residues leads to approximately a 10-fold decrease in potency, while removal of a further nine residues, encompassing two of the lanthionine rings, leads to a 100-fold decrease. There are some differences between analogous fragments of nisin and subtilin, suggesting possible subtle differences in mode of action. Cleavage within, or removal of, lanthionine ring C essentially abolishes the activity of nisin. The fragment nisin1-12 is inactive itself, and specifically antagonises the growth-inhibitory action of nisin. These results are discussed in terms of current models for the mechanism of action of nisin.

Amino Acid Sequence↗

PubMed1999

Chemistry, biochemistry, nutrition, and microbiology of lysinoalanine, lanthionine, and histidinoalanine in food and other proteins.

Heat and alkali treatments of foods, widely used in food processing, result in the formation of dehydro and cross-linked amino acids such as dehydroalanine, methyldehydroalanine, beta-aminoalanine, lysinoalanine (LAL), ornithinoalanine, histidinoalanine (HAL), phenylethylaminoalanine, lanthionine (LAN), and methyl-lanthionine present in proteins and are frequently accompanied by concurrent racemization of L-amino acid isomers to D-analogues. The mechanism of LAL formation is a two-step process: first, hydroxide ion-catalyzed elimination of H(2)S from cystine and H(2)O, phosphate, and glycosidic moieties from serine residues to yield a dehydroalanine intermediate; second, reaction of the double bond of dehydroalanine with the epsilon-NH(2) group of lysine to form LAL. Analogous elimination-addition reactions are postulated to produce the other unusual amino acids. Processing conditions that favor these transformations include high pH, temperature, and exposure time. Factors that minimize LAL formation include the presence of SH-containing amino acids, sodium sulfite, ammonia, biogenic amines, ascorbic acid, citric acid, malic acid, and glucose; dephosphorylation of O-phosphoryl esters; and acylation of epsilon-NH(2) groups of lysine. The presence of LAL residues along a protein chain decreases digestibility and nutritional quality in rodents and primates but enhances nutritional quality in ruminants. LAL has a strong affinity for copper and other metal ions and is reported to induce enlargement of nuclei of rats and mice but not of primate kidney cells. LAL, LAN, and HAL also occur naturally in certain peptide and protein antibiotics (cinnamycin, duramycin, epidermin, nisin, and subtilin) and in body organs and tissues (aorta, bone, collagen, dentin, and eye cataracts), where their formation may be a function of the aging process. These findings are not only of theoretical interest but also have practical implications for nutrition, food safety, and health. Further research needs are suggested for each of these categories. These overlapping aspects are discussed in terms of general concepts for a better understanding of the impact of LAL and related compounds in the diet. Such an understanding can lead to improvement in food quality and safety, nutrition, microbiology, and human health.

Alanine↗

PubMed2002

Biomimetic stereoselective formation of methyllanthionine.

Fmoc-(2R,3S)-3-methyl-Se-phenylselenocysteine was used for the synthesis of dehydrobutyrine (Dhb)-containing peptides. Biomimetic cyclization via Michael addition of Cys to a Dhb yielded the B-ring of the lantibiotic subtilin as a single diastereomer. The methyllanthionine product was shown to have the natural configuration by preparation of the authentic stereoisomer. The formation of a single isomer suggests that the prepeptide has a strong intrinsic preference for the stereochemistry observed in lantibiotics. [reaction: see text]

Alanine↗

PubMed2000

Solvent extraction of bacteriocins from liquid cultures.

A solvent extraction method was developed to concentrate lacidin from the culture of Lactobacillus acidophilus OSU133. The new method concentrates the bacteriocin at the interface between chloroform and the aqueous culture of the producing bacterium. Compared with other extraction procedures, the new method effectively recovers higher bacteriocin yield and results in relatively clean preparations. Recovery of lacidin by the chloroform extraction procedure, compared with ammonium sulphate precipitation and cell acidification methods, was >10-fold and about 100-fold greater, respectively. The new extraction procedure saves time and is easy to perform. This method is also effective in recovering subtilin, bacillicin, pediocin and nisin from cultures of Bacillus subtilis ATCC 6633, B. subtilis OSY1115/C, Pediococcus acidilactici PO2 and Lactococcus lactis ATCC 11454, respectively.

Ammonium Sulfate↗

PubMed1998

Identification and characterization of the structural and transporter genes for, and the chemical and biological properties of, sublancin 168, a novel lantibiotic produced by Bacillus subtilis 168.

An antimicrobial peptide produced by Bacillus subtilis 168 was isolated and characterized. It was named sublancin 168, and its behavior during Edman sequence analysis and its NMR spectrum suggested that sublancin is a dehydroalanine-containing lantibiotic. A hybridization probe based on the peptide sequence was used to clone the presublancin gene, which encoded a 56-residue polypeptide consisting of a 19-residue leader segment and a 37-residue mature segment. The mature segment contained one serine, one threonine, and five cysteine residues. Alkylation of mature sublancin showed no free sulfhydryl groups, suggesting that one sulfydryl had formed a beta-methyllanthionine bridge with a dehydrobutyrine derived by posttranslational modification of threonine; with the other four cysteines forming two disulfide bridges. It is unprecedented for a lantibiotic to contain a disulfide bridge. The sublancin leader was similar to known type AII lantibiotics, containing a double-glycine motif that is typically recognized by dual-function transporters. A protein encoded immediately downstream from the sublancin gene possessed features of a dual-function ABC transporter with a proteolytic domain and an ATP-binding domain. The antimicrobial activity spectrum of sublancin was like other lantibiotics, inhibiting Gram-positive bacteria but not Gram-negative bacteria; and like the lantibiotics nisin and subtilin in its ability to inhibit both bacterial spore outgrowth and vegetative growth. Sublancin is an extraordinarily stable lantibiotic, showing no degradation or inactivation after being stored in aqueous solution at room temperature for 2 years. The fact that sublancin is a natural product of B. subtilis 168, for which a great deal of genetic information is available, including the entire sequence of its genome, suggests that sublancin will be an especially good model for studying the potential of lantibiotics as sources of novel biomaterials.

ATP-Binding Cassette Transporters↗

PubMed2001

New gene cluster for lantibiotic streptin possibly involved in streptolysin S formation.

Streptolysin S (SLS) is a serum-extractable and oxygen-stable hemolysin produced by Group A Streptococcus. A SLS-deficient mutant in which transposon Tn 916 was inserted in a locus distinct from the sag gene cluster [Nizet et al. (2000) Infect. Immun. 68, 4245-4254] was obtained by filter mating of the transposon-harbouring Enterococcus faecalis strain and Streptococcus pyogenes BL(T). This mutant, N22, had completely lost the hemolytic activity, in consequence of insertion of a single Tn 916 into a hitherto-unknown lantibiotic gene cluster composed of 10 open reading frames. The arrangement and sequence of this lantibiotic gene cluster were similar to those of nisin and subtilin, and so we designated this new lantibiotic as streptin. The bactericidal activity of streptin was abolished on treatment with trypsin or proteinase K. The different host range and nucleotide sequence clearly distinguished streptin from streptococcins. Streptin was not hemolytic and its bacteriocin activity was independent of carrier oligonucleotides effective for SLS. The fact that N22 also lost the anti-bacterial activity against indicator streptococci reveals that the factor(s) required for lantibiotic formation plays an important role in SLS formation as well.

Anti-Bacterial Agents↗

PubMed2006

C terminus of NisI provides specificity to nisin.

Nisin-producing Lactococcus lactis protects its own cell membrane against the bacteriocin with the ABC transporter NisFEG, and the immunity lipoprotein NisI. In this study, in order to localize a site for specific nisin interaction in NisI, a C-terminal deletion series of NisI was constructed, and the C-terminally truncated NisI proteins were expressed in L. lactis. The shortest deletion (5 aa) decreased the nisin immunity capacity considerably in the nisin-negative strain MG1614, resulting in approximately 78% loss of immunity function compared with native NisI. A deletion of 21 aa decreased the immunity level even more, but longer deletions, up to 74 aa, provided the same level of nisin immunity as the 21 aa deletion, i.e. approximately 14% of the immunity provided by native NisI. Similar to native NisI, all the C-terminally truncated NisI proteins provided higher immunity to nisin in the NisFEG-expressing strain NZ9840 than in MG1614, i.e. approximately 40-50% of the immunity capacity of native NisI. Then, it was determined whether the NisI C-terminal 21 aa fragment could protect cells against nisin. To target the 21 aa fragment to its natural location, 21 C-terminal amino acids from the subtilin-specific immunity lipoprotein SpaI were replaced by 21 C-terminal amino acids from NisI. The expression of the SpaI'-'NisI fusion in L. lactis strains significantly increased their nisin immunity. This is the first time the immunity function of a lantibiotic immunity protein has been transferred to another protein. However, unlike native NisI, and the C-terminally truncated NisI fragments, the increase in nisin immunity conferred by the SpaI'-'NisI fusion was the same in both the NisFEG strain NZ9840 and MG1614. In conclusion, the SpaI'-'NisI fusion could not enhance nisin immunity by interacting with NisFEG, whereas the C-terminally truncated NisI fragments and native NisI were able to enhance nisin immunity, probably by co-operation with NisFEG. The results made it evident that the C terminus of NisI is involved in specific interaction with nisin, and that it confers specificity for the NisI immunity lipoprotein.

Anti-Bacterial Agents↗

PubMed1995

Elucidation of the primary structure of the lantibiotic epilancin K7 from Staphylococcus epidermidis K7. Cloning and characterisation of the epilancin-K7-encoding gene and NMR analysis of mature epilancin K7.

Lantibiotics are bacteriocins that contain unusual amino acids such as lanthionines and alpha, beta-didehydro residues generated by posttranslational modification of a ribosomally synthesized precursor protein. The structural gene encoding the novel lantibiotic epilancin K7 from Staphylococcus epidermidis K7 was cloned and its nucleotide sequence was determined. The gene, which was named elkA, codes for a 55-residue preprotein, consisting of an N-terminal 24-residue leader peptide, and a C-terminal 31-residue propeptide which is posttranslationally modified and processed to yield mature epilancin K7. In common with the type-A lantibiotics nisin A and nisin Z, subtilin, epidermin, gallidermin and Pep5, pre-epilancin K7 has a so-called class-Al leader peptide. Downstream and upstream of the elkA gene, the starts of two open-reading-frames, named elkP and elkT, were identified. The elkP and elkT genes presumably encode a leader peptidase and a translocator protein, respectively, which may be involved in the processing and export of epilancin K7. The amino acid sequence of the unmodified pro-epilancin K7, deduced from the elkA gene sequence, is in full agreement with the amino acid sequence of mature epilancin K7, determined previously by means of NMR spectroscopy [van de Kamp, M., Horstink, L. M., van den Hooven, M. W., Konings, R. N. M., Hilbers, C. W., Sahl, H.-G., Metzger, J. W. & van de Ven, F. J. M. (1995) Eur. J. Biochem. 227, 757-771]. The first residue of mature epilancin K7 appears to be modified in a way that has not been described for any other lantibiotic so far. NMR experiments show that the elkA-encoded serine residue at position +1 of pro-epilancin K7 is modified to a 2-hydroxypropionyl residue in the mature protein.

Amino Acid Sequence↗

PubMed1996

Surface location and orientation of the lantibiotic nisin bound to membrane-mimicking micelles of dodecylphosphocholine and of sodium dodecylsulphate.

The interaction of nisin, a membrane-interacting cationic polypeptide, with membrane-mimicking micelles of zwitterionic dodecylphosphocholine and of anionic sodium dodecylsulphate was studied. Direct contacts have been established through the observation of NOEs between nisin and micelle protons. Spin-labeled DOXYL-stearic acids were incorporated into the two micellar systems. From the paramagnetic broadening effects induced in the 1H-NMR spectrum of nisin it is concluded that the molecule is localized at the surface of the micelles. The interactions of nisin with zwitterionic and with anionic micelles resemble each other as do the nisin conformations [van den Hooven, H. W., Doeland, C. C. M., van de Kamp, M., Konings, R. N. H., Hilbers, C. W. & van de Ven, F. J. M. (1995) Eur J. Biochem. 235, 382-393]. The hydrophobic residues are immersed into the micelles and oriented towards the center, whereas the more polar or charged residues have an outward orientation. The micellar systems are considered to model the first step in the mechanism of antimicrobial action of nisin, this step is the binding of nisin to the cytoplasmic membrane of target bacteria. Detailed information on this initial binding step is obtained. Hydrophobic and electrostatic interactions appear to be involved in the nisin-micelle contacts. It is suggested that subtilin, a lantibiotic structurally related to nisin, has a comparable membrane interaction surface.

Amino Acid Sequence↗

PubMed1992

Cross-reactivity of bacteriocins from lactic acid bacteria and lantibiotics in a nisin bioassay and ELISA.

A number of bacteriocins from lactic acid bacteria and lantibiotics were tested for cross-reactivity in a nisin ELISA and bioassay. The bacteriocins showed no cross-reactivity, reflecting their structural dissimilarity from nisin. The lantibiotic subtilin which shares many common structural features with nisin, showed a high cross-reactivity in both the ELISA and the bioassay suggesting possible modifications to nisin to enhance its activity. Gallidermin did not cross react in the ELISA but did produce a zone of inhibition in the less specific bioassay. Other lantibiotics tested did not react in either assay.

Anti-Bacterial Agents↗

PubMed1985

Structural similarities of the staphylococcin-like peptide Pep-5 to the peptide antibiotic nisin.

The staphylococcin-like peptide Pep-5 was shown to be a complex mixture of closely related and strongly basic peptides. Five peptides were purified by high-pressure liquid chromatography on reversed-phase and gel filtration columns and further characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and amino acid analysis. Four peptides have molecular weights of ca. 3,500, whereas one is of double size. All contain the thioether amino acid lanthionine and a large number of lysine residues per molecule. The amino terminus of the main active peptide is blocked; the carboxy-terminal end is formed by a lysine residue. The data obtained for Pep-5 suggest striking structural similarities to the peptide antibiotics nisin and subtilin.

Alanine↗

PubMed2006

The lantibiotic mersacidin is an autoinducing peptide.

The lantibiotic (lanthionine-containing antibiotic) mersacidin is an antimicrobial peptide consisting of 20 amino acids and is produced by Bacillus sp. strain HIL Y-85,54728. The structural gene (mrsA) and the genes for producer self-protection, modification enzymes, transport proteins, and regulator proteins are organized in a 12.3-kb biosynthetic gene cluster on the chromosome of the producer strain. Mersacidin is produced in stationary phase in a synthetic medium (K. Altena, A. Guder, C. Cramer, and G. Bierbaum, Appl. Environ. Microbiol. 66:2565-2571, 2000). To investigate the influence of the alternative sigma factor H on mersacidin biosynthesis, a SigH knockout was constructed. The knockout mutant was asporogenous, and a comparison to the wild-type strain indicated no significant differences concerning mersacidin production and immunity. Characterization of the mrsA promoter showed that the gene is transcribed by the housekeeping sigma factor A. The biosynthesis of some lantibiotic peptides like nisin or subtilin is regulated in a cell-density-dependent manner (M. Kleerebezem, Peptides 25:1405-1414, 2004). When mersacidin was added at a concentration of 2 mg/liter to an exponentially growing culture, an earlier production of antibacterial activity against Micrococcus luteus ATCC 4698 in comparison to that of the control culture was observed, suggesting that mersacidin itself functions as an autoinducer. In real-time PCR experiments, the expression of mrsA was remarkably increased in the induced culture compared to the control. In conclusion, mersacidin is yet another lantibiotic peptide whose biosynthesis can be regulated by an autoinducing mechanism.

Anti-Bacterial Agents↗

PubMed1992

Biosynthesis of the lantibiotic nisin: genomic organization and membrane localization of the NisB protein.

Nisin produced by Lactococcus lactis 6F3 is used as a food preservative and is the most important member of a group of peptide-antibiotics containing lanthionine bridges (lantibiotics) (N. Schnell, K.-D. Entian, U. Schneider, F. Götz, H. Zähner, R. Kellner, and G. Jung, Nature [London] 333:276-278, 1988). Nisin is ribosomally synthesized, and its structural gene, nisA, encodes a prepeptide that is posttranslationally modified, revealing the active lantibiotic (C. Kaletta and K.-D. Entian, J. Bacteriol. 171:1597-1601, 1989). Adjacent to nisA, the additional genes nisB, nisT, and nisC were identified. Over their entire sequences, these genes were homologous to genes recently identified as important for the biosynthesis of lantibiotics, that is, subtilin from Bacillus subtilis ATCC 6633 and epidermin from Staphylococcus epidermidis Tü 3298. Genes nisB, nisT, and nisC corresponded to open reading frames of 993, 600, and 418 amino acid residues, respectively. The nisT open reading frame is homologous to proteins of the HlyB (hemolysin B protein of Escherichia coli) subfamily. Proteins of this subfamily are responsible for the secretion of a variety of compounds, including large polypeptides, polysaccharides, and anti-drug tumors, indicating that NisT may be involved in nisin transport. Northern (RNA) blot analysis revealed a 0.3-kb transcript for the nisA structural gene, and the transcriptional start point of the nisA gene was determined by primer extension. Additionally, a mRNA of at least 3 kb was identified by using a hybridization probe specific to nisB. Antibodies were raised against the NisB protein, and Western blot (immunoblot) analysis revealed a molecular weight of about 115 kDa, which is in accordance with the theoretical protein size of 117.5 kDa as calculated from the nisB open reading frame. Several amphipathic transmembrane alpha-helices indicated that NisB is associated with the membrane. This was confirmed by preparing L. lactis vesicles. The NisB protein was tightly associated with the vesicle fraction and was released by sodium dodecyl sulfate treatment only. These results suggest that NisB is membrane associated and that nisin biosynthesis occurs at the cell membrane.

Amino Acid Sequence↗

PubMed1994

Regulation of nisin biosynthesis and immunity in Lactococcus lactis 6F3.

The biosynthetic genes of the nisin-producing strain Lactococcus lactis 6F3 are organized in an operon-like structure starting with the structural gene nisA followed by the genes nisB, nisT, and nisC, which are probably involved in chemical modification and secretion of the prepeptide (G. Engelke, Z. Gutowski-Eckel, M. Hammelmann, and K.-D. Entian, Appl. Environ. Microbiol. 58:3730-3743, 1992). Subcloning of an adjacent 5-kb downstream region revealed additional genes involved in nisin biosynthesis. The gene nisI, which encodes a lipoprotein, causes increased immunity after its transformation into nisin-sensitive L. lactis MG1614. It is followed by the gene nisP, coding for a subtilisin-like serine protease possibly involved in processing of the secreted leader peptide. Adjacent to the 3' end of nisP the genes nisR and nisK were identified, coding for a regulatory protein and a histidine kinase, showing marked similarities to members of the OmpR/EnvZ-like subgroup of two-component regulatory systems. The deduced amino acid sequences of nisR and nisK exhibit marked similarities to SpaR and SpaK, which were recently identified as the response regulator and the corresponding histidine kinase of subtilin biosynthesis. By using antibodies directed against the nisin prepeptide and the NisB protein, respectively, we could show that nisin biosynthesis is regulated by the expression of its structural and biosynthetic genes. Prenisin expression starts in the exponential growth phase and precedes that of the NisB protein by approximately 30 min. Both proteins are expressed to a maximum in the stationary growth phase.

Amino Acid Sequence↗