Previous Article | Next Article 
Applied and Environmental Microbiology, April 2005, p. 1959-1963, Vol. 71, No. 4
0099-2240/05/$08.00+0 doi:10.1128/AEM.71.4.1959-1963.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.
Sec-Mediated Secretion of Bacteriocin Enterocin P by Lactococcus lactis
Carmen Herranz and
Arnold J. M. Driessen*
Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Haren, The Netherlands
Received 16 July 2004/
Accepted 9 November 2004

ABSTRACT
Most lactic acid bacterium bacteriocins utilize specific leader
peptides and dedicated machineries for secretion. In contrast,
the enterococcal bacteriocin enterocin P (EntP) contains a typical
signal peptide that directs its secretion when heterologously
expressed in
Lactococcus lactis. Signal peptide mutations and
the SecA inhibitor azide blocked secretion. These observations
demonstrate that EntP is secreted by the Sec translocase.

INTRODUCTION
Ribosomally synthesized antimicrobial peptides (bacteriocins)
produced by lactic acid bacteria have potential applications
as biopreservatives in the food industry (
32). Enterocin P (EntP)
is a class IIa bacteriocin (
10) produced by
Enterococcus faecium P13. It inhibits the growth of some food spoilage and food-borne
pathogens, such as
Listeria monocytogenes,
Staphylococcus aureus,
and
Clostridium botulinum (
5). The genetic determinants responsible
for EntP production are organized in one operon comprising the
bacteriocin structural gene,
entP, and
orf2, encoding a putative
immunity protein (
5). The EntP precursor (preEntP) consists
of 71 amino acid residues (7.5 kDa) and contains a signal peptide
of 27 amino acids that is removed proteolytically upon secretion,
yielding the mature EntP (4.6 kDa).
The absence or presence (and type) of an N-terminal extension determines the secretion mechanism of class II bacteriocins. So far, the enterocins L50A, L50B, and Q (6) and the lactococcal bacteriocin LsbB (12) are the only examples of class II bacteriocins that are synthesized without N-terminal extension. The secretion mechanism of these enterocins is unknown, although LsbB has been reported to be secreted by LmrB, a multidrug resistance-like ABC transporter (12). Most class II bacteriocin precursors contain a double-glycine-type signal peptide and are translocated and processed by dedicated ABC transporters (15). Finally, preEntP and some other class II bacteriocins (5, 9, 22, 26, 37, 39) contain a typical Sec signal peptide (19) that is believed to direct these bacteriocins to the Sec translocase embedded in the cytoplasmic membranes (7). However, preEntP is a small, amphiphatic polypeptide that to some extent resembles procoat M13, the precursor of a small phage protein which does not utilize the Sec translocase despite containing a typical Sec-dependent signal sequence (2). Therefore, the objective of this work was to determine the secretion mechanism of preEntP.

MATERIALS AND METHODS
Bacterial strains, plasmids, and growth conditions.
The bacterial strains and plasmids used in this study are shown
in Table
1.
E. faecium P13 (
5) and T136 (
3) were used as an
EntP producer strain and sensitive indicator strain, respectively.
Enterococci were grown at 30°C in MRS broth (Oxoid Ltd.,
Basingstoke, United Kingdom).
Lactococcus lactis NZ9000 was
used in combination with the nisin-controlled expression system
(
20) for protein overexpression.
L. lactis was grown at 30°C
in M17 medium (Difco, Le Pont de Claix, France) supplemented
with 0.5% (wt/vol) glucose and 5 µg of chloramphenicol
per ml when appropriate. Chemically defined medium (CDM) (
21)
was used to grow
L. lactis for pulse-labeling experiments.
Recombinant DNA techniques.
Cloning and DNA manipulation were performed as described by
Sambrook et al. (
36). Oligonucleotide primers used for PCR are
shown in Table
2.
E. faecium P13 and
L. lactis MG1363 (
13) chromosomal
DNAs were used as templates for the PCR amplification of
entP (
5) and
usp45 (
38), respectively. The PCR overlap extension
method (
17) was used to introduce single-amino-acid substitutions
and to construct gene fusions of the signal peptides of preEntP
(SP
Ent) and preUsp45 (SP
Usp) to the mature regions of preUsp45
and preEntP, respectively. PCR products were cloned in frame
with a C-terminal hexahistidine tag on the pHLP5 expression
plasmid (
33). Sequencing of the PCR-amplified DNA fragments
was performed at Westburg Genomics (Leusden, The Netherlands).
Purification of histidine-tagged EntP and Usp45.
Ammonium sulfate (45% [wt/vol]) was gradually added to the culture
supernatants of
L. lactis NZ9000 cells producing C-terminal
hexahistidine-tagged EntP (EntP-His) or Usp45 (Usp45-His). After
centrifugation, the precipitated proteins were resuspended in
50 mM sodium phosphate buffer (pH 8.0) with 300 mM NaCl (buffer
A). Fractions were desalted by gel filtration (G-25 PD-10 columns,
Amersham Biosciences, Uppsala, Sweden) and mixed with Ni-nitrilotriacetic
acid (NTA) resin (QIAGEN, Hilden, Germany) equilibrated with
buffer A (pH 8.0), and suspensions were gently shaken overnight
at 4°C. The resin was transferred to a Bio-spin column (Bio-Rad,
Hercules, Calif.) and subsequently washed with 10 column volumes
of buffer A (pH 8.0) containing 75 or 10 mM imidazole for EntP-His
and Usp45-His, respectively. Proteins were eluted with buffer
A (pH 7.0) containing either 1 or 0.25 M imidazole for EntP-His
and Usp45-His, respectively. Eluted fractions were analyzed
by sodium dodecyl sulfate-polyacrylamide gel electrophoresis
(SDS-PAGE) and Western blotting using monoclonal antibodies
directed against the hexahistidine tag (Dianova, Hamburg, Germany)
for chemiluminiscence detection with the Lumi-Imager F1 (Roche
Diagnostics). N-terminal sequencing of EntP was performed at
the University of British Columbia (Vancouver, Canada).
Pulse-labeling analysis.
Overnight cultures of L. lactis cells transformed with the appropriate plasmids and grown on CDM were freshly diluted (1:40) in 5 ml of the same medium. After incubation at 30°C to an optical density at 660 nm of 0.6, cells were collected by centrifugation, washed, and resuspended in CDM without methionine. Nisin was added, and incubation at 30°C was continued for 30 min. Where stated, cells were treated with sodium azide prior to the pulse to inhibit Sec-dependent protein secretion. Pulse-labeling was performed by the addition of 16 µCi of the Pro-mix L-(35S) in vitro cell labeling mix per ml (Amersham Biosciences, Roosendaal, The Netherlands). During the chase, nonradioactive methionine (25 mM) and cysteine (10 mM) were added, and at various times, 500-µl samples were removed and immediately centrifuged. The proteins present in the supernatants were precipitated with trichloroacetic acid (TCA; 10% [vol/vol]). Precipitates were washed with 80% (vol/vol) ice-cold acetone, dried, resuspended in SDS-PAGE sample buffer, and analyzed by SDS-PAGE and phosphorimaging. Cell pellets were resuspended in 100 µl of lysis buffer (50 mM NaCl, 10 mM EDTA, 20% [wt/vol] sucrose, 10 mM Tris, pH 8.1, and 10 mg of lysozyme per ml) and incubated at 50°C for 10 min. Next, 10 µl of 10% (wt/vol) SDS was added, and after boiling for 10 min, the samples were diluted 10 times with buffer A (pH 8.0) containing 0.05% (wt/vol) dodecyl-ß-D-maltoside (Anatrace, Maumee, Ohio) and 100 µl of pre-equilibrated Ni-NTA resin. After 2 h at 4°C with shaking, proteins were eluted with buffer A (pH 7.0) containing 0.05% (wt/vol) DDM and 250 mM imidazole and further analyzed as described above.
Antimicrobial activity assays.
The antimicrobial activity of EntP-His was measured by the agar well-diffusion assay (4) and quantified by a microtiter plate assay (18) using E. faecium T136 (3) as the indicator microorganism.

RESULTS
Heterologous expression of entP in L. lactis.
Production of EntP-His (6 kDa) in
L. lactis NZ9000 was achieved
when cells containing
entP were induced with nisin. Coomassie-stained
SDS-PAGE of the protein purified by Ni-NTA affinity chromatography
showed a single band that corresponded to EntP-His (Fig.
1),
as verified by N-terminal sequence analysis of the first six
amino acid residues. This result indicates that preEntP is processed
by
L. lactis in an identical manner as in
E. faecium. The heterologously
produced EntP-His displayed antimicrobial activity against
E. faecium T136 (not shown).
Signal peptide swapping between preEntP and preUsp45.
Hybrid genes encoding the precursor proteins composed of the
SP
Ent fused to the mature Usp45 (
entP-
usp45) and vice versa
(
usp45-entP), were constructed. Expression of
entP-
usp45 resulted
in high-level production of a protein of 50 to 75 kDa (Fig.
2) that corresponded to Usp45-His, as verified by Western blotting
(results not shown). Although the native signal peptide supported
more efficient secretion of Usp45-His (Fig.
2), the data show
that the SP
Ent can direct the secretion of a Sec-dependent protein.
Nisin induction of
L. lactis cells containing
usp45-
entP resulted
in the production of EntP-His (Fig.
3A), which displayed a normal
antimicrobial activity (Fig.
3B). These results show that the
SP
Ent and the SP
Usp are functionally exchangeable and indicate
that the SP
Ent is a typical Sec-dependent signal peptide.
Secretion of EntP-His directed by mutated signal peptides.
To further investigate the characteristics of the SP
Ent, point
mutations were introduced into its hydrophobic core. Replacement
of the isoleucine residues at positions 11 and 13 with asparagine
and of the glycine at position 12 with lysine, yielded the mutated
signal peptides I11N, I13N, and G12K, respectively. Analysis
of the secretion of EntP-His by a microtiter plate assay showed
that only 0.6, 0.5, and 2.5% of the antimicrobial activity produced
by the cells expressing the wild-type precursor was obtained
when secretion was directed by the mutated signal peptides I11N,
G12K, and I13N, respectively.
Effect of azide on EntP secretion.
Azide, a potent inhibitor of SecA, blocks Sec-dependent protein secretion in Escherichia coli and Bacillus subtilis (29, 31). The effect of azide on the SPEnt-mediated secretion in L. lactis was evaluated by using pulse-labeling assays. Secretion of EntP-His or Usp45-His directed by the SPEnt was drastically reduced in the presence of azide (Fig. 4A and B), while for SPEnt-Usp45-His, the amount of precursor remaining inside the cells increased (Fig. 4C). Similarly, secretion of preUsp45-His was blocked by azide (results not shown). These data indicate that EntP secretion in L. lactis is mediated by the Sec translocase.

DISCUSSION
In this report, we have investigated the mechanism of secretion
of the heterologously produced EntP-His in
L. lactis. EntP belongs
to the class II bacteriocins that are synthesized as precursors
with an N-terminal extension that shows the typical tripartite
structure of Sec-dependent signal peptides (
19) (Table
3). The
assumption of a Sec-dependent secretion of bacteriocin 31 and
acidocin B is supported by their production by heterologous
hosts in which only the bacteriocin structural and immunity
genes have been introduced (
22,
37). For divergicin A, additional
evidence is provided by the ability of its signal peptide to
direct the secretion of Sec-dependent (
39) and Sec-independent
(
1,
27,
28) proteins. In the case of EntP, the presence of a
seemingly typical signal sequence (
5) and the lack of dedicated
transport genes in the
entP operon (
16) suggested that this
bacteriocin is secreted via the Sec pathway. However, there
are some unusual characteristics in the preEntP amino acid sequence
which prompted us to investigate its secretion mechanism. First,
there is a positively charged residue at the +3 position of
the mature EntP. Although this feature is not uncommon in class
II bacteriocins secreted by dedicated ABC transporters, the
presence of positively charged amino acids in the N-terminal
region of the mature proteins negatively affects Sec-dependent
secretion in
E. coli (
25) and
L. lactis (
23,
24). Second, a
lysine residue is present at position 4 relative to the
cleavage site in preEntP. This attribute is not observed in
other putative Sec-dependent class II bacteriocins and would
render the signal peptide inactive for Sec-dependent secretion
in
E. coli. Finally, asparagine, a residue rarely present in
prokaryotic signal peptides (
14), is located in the hydrophobic
core of SP
Ent.
Since no dedicated transporter has been defined for EntP, the
signal sequence should support its secretion via the Sec translocase
when expressed in a heterologous host. Indeed,
L. lactis could
secrete EntP-His either with the native or with the Usp45 signal
peptide. On the other hand, secretion of a typical Sec substrate
as Usp45 (
38) is supported by the SP
Ent. Finally, secretion
is dramatically reduced by signal sequence mutations that interfere
with the secretion of Sec-dependent substrates in
E. coli (
14)
and is blocked by the SecA inhibitor azide. Taken together,
these results lend strong support for the hypothesis that EntP
is secreted into the medium by the Sec translocase.
In an attempt to detect special features of the SPEnt that could be required for the bacteriocin secretion, the ability of the SPUsp to direct EntP-His secretion was evaluated. Previous work using SPUsp for heterologous protein expression showed that the combination of this signal peptide with a negatively charged N terminus in the mature protein increased the secretion efficiency (8, 24, 34). Combination with the cationic N terminus of EntP appears at least as efficient as the native SPEnt. Apparently, the positive charge in the mature amino terminus does not interfere with a proper functioning of the SPUsp in L. lactis.
Several bacteriocins have been heterologously produced in L. lactis, using an ABC-dedicated transport system (reviewed in reference 35). However, a limited number (28, 30, 39) have been produced through secretion by the Sec system. This study shows that L. lactis is an excellent host for the production of Sec-dependent bacteriocins. Since L. lactis is not sensitive to EntP (5), the bacteriocin could be expressed without the immunity protein Orf2. This makes the food-grade microorganism L. lactis an ideal host for the heterologous production of EntP, thereby avoiding concerns about the safety of enterococci in food (11).

ACKNOWLEDGMENTS
Luis M. Cintas and Pablo E. Hernández are acknowledged
for kindly supplying
E. faecium strains P13 and T136. We are
grateful to Girbe Buist, Jan Jongbloed, Nico Nouwen, and Aldert
Zomer for helpful advice with pulse-labeling experiments and
to Nathalie Campo and Piotr Mazurkiewicz for stimulating discussions.
C. Herranz is supported by a Marie Curie Individual Fellowship (contract HPMF-CT-2002-01660) from the IHP Programme of the European Commission.

FOOTNOTES
* Corresponding author. Mailing address: Department of Microbiology, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands. Phone: 31 50 3632164. Fax: 31 50 3632154. E-mail:
a.j.m.driessen{at}rug.nl.


REFERENCES
1 - Biet, F., J. M. Berjeaud, R. W. Worobo, Y. Cenatiempo, and C. Fremaux. 1998. Heterologous expression of the bacteriocin mesentericin Y105 using the dedicated transport system and the general secretory pathway. Microbiology 144:2845-2854.[Abstract/Free Full Text]
2 - Cao, G., S. Cheng, P. Whitley, G. von Heijne, A. Kuhn, and R. E. Dalbey. 1994. Synergistic insertion of two hydrophobic regions drives Sec-independent membrane protein assembly. J. Biol. Chem. 269:26898-26903.[Abstract/Free Full Text]
3 - Casaus, M. P., T. Nilsen, L. M. Cintas, I. F. Nes, P. E. Hernández, and H. Holo. 1997. Enterocin B, a new bacteriocin from Enterococcus faecium T136 which can act synergistically with enterocin A. Microbiology 143:2287-2294.[Abstract/Free Full Text]
4 - Cintas, L. M., J. M. Rodríguez, M. F. Fernandez, K. Sletten, I. F. Nes, P. E. Hernandez, and H. Holo. 1995. Isolation and characterization of pediocin L50, a new bacteriocin from Pediococcus acidilactici with a broad inhibitory spectrum. Appl. Environ. Microbiol. 61:2643-2648.[Abstract]
5 - Cintas, L. M., P. Casaus, L. S. Håvarstein, P. E. Hernández, and I. F. Nes. 1997. Biochemical and genetic characterization of enterocin P, a novel sec-dependent bacteriocin from Enterococcus faecium P13 with a broad antimicrobial spectrum. Appl. Environ. Microbiol. 63:4321-4330.[Abstract]
6 - Cintas, L. M., P. Casaus, C. Herranz, L. S. Håvarstein, H. Holo, P. E. Hernández, and I. F. Nes. 2000. Biochemical and genetic evidence that Enterococcus faecium L50 produces enterocins L50A and L50B, the sec-dependent enterocin P, and a novel bacteriocin secreted without an N-terminal extension termed enterocin Q. J. Bacteriol. 182:6806-6814.[Abstract/Free Full Text]
7 - de Keyzer, J., C. van der Does, and A. J. M. Driessen. 2003. The bacterial translocase: a dynamic protein channel complex. Cell. Mol. Life Sci. 60:2034-2052.[CrossRef][Medline]
8 - Dieye, Y., S. Usai, F. Clier, A. Gruss, and J.-C. Piard. 2001. Design of a protein-targeting system for lactic acid bacteria. J. Bacteriol. 183:4157-4166.[Abstract/Free Full Text]
9 - Doi, K., T. Eguchi, S.-H. Choi, A. Iwatake, S. Ohmomo, and S. Ogata. 2002. Isolation of enterocin SE-K4-encoding plasmid and a high enterocin SE-K4 producing strain of Enterococcus faecalis K-4. J. Biosci. Bioeng. 93:434-436.
10 - Ennahar, S., T. Sashihara, K. Sonomoto, and A. Ishizaki. 2000. Class IIa bacteriocins: biosynthesis, structure and activity. FEMS Microbiol. Rev. 24:85-106.[CrossRef][Medline]
11 - Franz, C. M., M. E. Stiles, K. H. Schleifer, and W. H. Holzapfel. 2003. Enterococci in foodsa conundrum for food safety. Int. J. Food Microbiol. 88:105-122.[CrossRef][Medline]
12 - Gajic, O., G. Buist, M. Kojic, L. Topisirovic, O. P. Kuipers, and J. Kok. 2003. Novel mechanism of bacteriocin secretion and immunity carried out by lactococcal multidrug resistance proteins. J. Biol. Chem. 36:34291-34298.
13 - Gasson, M. J. 1983. Plasmid complements of Streptococcus lactis NCDO 712 and other lactic acid streptococci after protoplast-induced curing. J. Bacteriol. 154:1-9.[Abstract/Free Full Text]
14 - Goldstein, J., S. Lehnhardt, and M. Inouye. 1991. In vivo effect of asparagine in the hydrophobic region of the signal sequence. J. Biol. Chem. 266:14413-14417.[Abstract/Free Full Text]
15 - Håvarstein, L. S., D. B. Diep, and I. F. Nes. 1995. A family of bacteriocin ABC transporters carry out proteolytic processing of their substrates concomitant with export. Mol. Microbiol. 16:229-240.[Medline]
16 - Herranz, C. 2001. Ph.D. thesis. Universidad Complutense de Madrid, Madrid, Spain.
17 - Higuchi, R., B. Krummel, and R. K. Saiki. 1988. A general method of in vitro preparation and specific mutagenesis of DNA fragments: study of protein and DNA interactions. Nucleic Acids Res. 16:7351-7367.[Abstract/Free Full Text]
18 - Holo, H., Ø. Nilssen, and I. F. Nes. 1991. Lactococcin A, a new bacteriocin from Lactococcus lactis subsp. cremoris: isolation and characterization of the protein and its gene. J. Bacteriol. 173:3879-3887.[Abstract/Free Full Text]
19 - Izard, J. W., and D. A. Kendall. 1994. Signal peptides: exquisitely designed transport promoters. Mol. Microbiol. 13:765-773.[CrossRef][Medline]
20 - Kuipers, O. P., P. G. de Ruyter, M. Kleerebezen, and W. M. de Vos. 1998. Quorum sensing-controlled gene expression in lactic acid bacteria. J. Biotechnol. 64:15-21.
21 - Kunji, E., I. Mierau, B. Poolman, W. N. Konings, G. Venema, and J. Kok. 1996. Fate of peptides in peptidase mutants of Lactococcus lactis. Mol. Microbiol. 21:123-131.[CrossRef][Medline]
22 - Leer, J. R., J. M. B. van der Vosse, M. van Gieze, J. M. van Noort, and P. H. Pouwels. 1995. Genetic analysis of acidocin B, a novel bacteriocin produced by Lactobacillus acidophilus. Microbiology 141:1629-1635.[Abstract/Free Full Text]
23 - Le Loir, Y., A. Gruss, S. D. Ehrlich, and P. Langella. 1998. A nine-residue synthetic propeptide enhances secretion efficiency of heterologous proteins in Lactococcus lactis. J. Bacteriol. 180:1895-1903.[Abstract/Free Full Text]
24 - Le Loir, Y., S. Nouaille, J. Commissaire, L. Brétigny, A. Gruss, and P. Langella. 2001. Signal peptide and propeptide optimization for heterologous protein secretion in Lactococcus lactis. Appl. Environ. Microbiol. 67:4119-4127.[Abstract/Free Full Text]
25 - Li, P., J. Beckwith, and H. Inouye. 1988. Alteration of the amino terminus of the mature sequence of a periplasmic protein can severely affect protein export in Escherichia coli. Proc. Natl. Acad. Sci. USA 85:7685-7689.[Abstract/Free Full Text]
26 - Martínez, B., M. Fernández, J. E. Suárez, and A. Rodríguez. 1999. Synthesis of lactococcin 972, a bacteriocin produced by Lactococcus lactis IPLA 972, depends on the expression of a plasmid-encoded bicistronic operon. Microbiology 145:3155-3161.[Abstract/Free Full Text]
27 - McCormick, J. K., R. W. Worobo, and M. E. Stiles. 1996. Expression of the antimicrobial peptide carnobacteriocin B2 by a signal peptide-dependent general secretory pathway. Appl. Environ. Microbiol. 62:4095-4099.[Abstract]
28 - McCormick, J. K., T. R. Klaenhammer, and M. E. Stiles. 1999. Colicin V can be produced by lactic acid bacteria. Lett. Appl. Microbiol. 29:37-41.[CrossRef][Medline]
29 - Meens, J., E. Frings, M. Klose, and R. Freudl. 1993. An outer membrane protein (OmpA) of Escherichia coli can be translocated across the cytoplasmic membrane of Bacillus subtilis. Mol. Microbiol. 9:847-855.[Medline]
30 - Nouaille, S., L. A. Ribeiro, A. Miyoshi, D. Pontes, Y. Le Loir, S. C. Oliveira, P. Langella, and V. Azevedo. 2003. Heterologous protein production and delivery systems for Lactococcus lactis. Genet. Mol. Res. 2:102-111.[Medline]
31 - Oliver, D. B., R. J. Cabelli, K. M. Dolan, and G. P. Jarosik. 1990. Azide-resistant mutants of Escherichia coli alter the SecA protein, an azide-sensitive component of the protein export machinery. Proc. Natl. Acad. Sci. USA 87:8227-8231.[Abstract/Free Full Text]
32 - O'Sullivan, L., R. P. Ross, and C. Hill. 2002. Potential of bacteriocin-producing lactic acid bacteria for improvements in food safety and quality. Biochimie 84:593-604.[Medline]
33 - Putman, M., H. W. van Veen, B. Poolman, and W. N. Konings. 1999. Restrictive use of detergents in the functional reconstitution of the secondary multidrug transporter LmrP. Biochemistry 38:1002-1008.[CrossRef][Medline]
34 - Ribeiro, L. A., V. Azevedo, Y. Le Loir, S. C. Oliveira, Y. Dieye, J.-C. Piard, A. Gruss, and P. Langella. 2002. Production and targeting of the Brucella abortus antigen L7/L12 in Lactococcus lactis: a first step towards food-grade live vaccines against brucellosis. Appl. Environ. Microbiol. 68:910-916.[Abstract/Free Full Text]
35 - Rodríguez, J. M., M. I. Martínez, N. Horn, and H. M. Dodd. 2002. Heterologous production of bacteriocins by lactic acid bacteria. Int. J. Food Microbiol. 80:101-116.
36 - Sambrook, J., E. F. Fritsch, and T. Maniatis. 1989. Molecular cloning: a laboratory manual, 2nd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.
37 - Tomita, H., S. Fujimoto, K. Tanimoto, and Y. Ike. 1996. Cloning and genetic organization of the bacteriocin 31 determinant encoded on the Enterococcus faecalis pheromone-responsive conjugative plasmid pYI17. J. Bacteriol. 178:3585-3593.[Abstract/Free Full Text]
38 - van Asseldonk, M., W. M. de Vos, and G. Simons. 1993. Functional analysis of the Lactococcus lactis usp45 secretion signal in the secretion of a homologous proteinase and a heterologous alpha-amylase. Mol. Gen. Genet. 240:428-434.[CrossRef][Medline]
39 - Worobo, R. W., M. J. van Belkum, M. Sailer, K. L. Roy, J. C. Vederas, and M. E. Stiles. 1995. A signal peptide secretion-dependent bacteriocin from Carnobacterium divergens. J. Bacteriol. 177:3143-3149.[Abstract/Free Full Text]
Applied and Environmental Microbiology, April 2005, p. 1959-1963, Vol. 71, No. 4
0099-2240/05/$08.00+0 doi:10.1128/AEM.71.4.1959-1963.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.
This article has been cited by other articles:
-
Izquierdo, E., Cai, Y., Marchioni, E., Ennahar, S.
(2009). Genetic Identification of the Bacteriocins Produced by Enterococcus faecium IT62 and Evidence that Bacteriocin 32 Is Identical to Enterocin IT. Antimicrob. Agents Chemother.
53: 1907-1911
[Abstract]
[Full Text]
-
Izquierdo, E., Bednarczyk, A., Schaeffer, C., Cai, Y., Marchioni, E., Van Dorsselaer, A., Ennahar, S.
(2008). Production of Enterocins L50A, L50B, and IT, a New Enterocin, by Enterococcus faecium IT62, a Strain Isolated from Italian Ryegrass in Japan. Antimicrob. Agents Chemother.
52: 1917-1923
[Abstract]
[Full Text]
-
Sanchez, J., Borrero, J., Gomez-Sala, B., Basanta, A., Herranz, C., Cintas, L. M., Hernandez, P. E.
(2008). Cloning and Heterologous Production of Hiracin JM79, a Sec-Dependent Bacteriocin Produced by Enterococcus hirae DCH5, in Lactic Acid Bacteria and Pichia pastoris. Appl. Environ. Microbiol.
74: 2471-2479
[Abstract]
[Full Text]
-
Kuipers, A., Wierenga, J., Rink, R., Kluskens, L. D., Driessen, A. J. M., Kuipers, O. P., Moll, G. N.
(2006). Sec-Mediated Transport of Posttranslationally Dehydrated Peptides in Lactococcus lactis. Appl. Environ. Microbiol.
72: 7626-7633
[Abstract]
[Full Text]
-
Criado, R., Diep, D. B., Aakra, A., Gutierrez, J., Nes, I. F., Hernandez, P. E., Cintas, L. M.
(2006). Complete Sequence of the Enterocin Q-Encoding Plasmid pCIZ2 from the Multiple Bacteriocin Producer Enterococcus faecium L50 and Genetic Characterization of Enterocin Q Production and Immunity.. Appl. Environ. Microbiol.
72: 6653-6666
[Abstract]
[Full Text]
-
Drider, D., Fimland, G., Hechard, Y., McMullen, L. M., Prevost, H.
(2006). The Continuing Story of Class IIa Bacteriocins. Microbiol. Mol. Biol. Rev.
70: 564-582
[Abstract]
[Full Text]