scholarly journals Conjugative Plasmid from Lactobacillus gasseri LA39 That Carries Genes for Production of and Immunity to the Circular Bacteriocin Gassericin A

2009 ◽  
Vol 75 (19) ◽  
pp. 6340-6351 ◽  
Author(s):  
Yoshiyuki Ito ◽  
Yasushi Kawai ◽  
Kensuke Arakawa ◽  
Yoshiko Honme ◽  
Takashi Sasaki ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Lactobacillus Reuteri ◽  
Plasmid Vector ◽  
Open Reading Frames ◽  
Conjugative Plasmid ◽  
Lactobacillus Gasseri ◽  
Plasmid Maintenance ◽  
Circular Bacteriocin ◽  
Derivative Plasmid ◽  
Host Killing

ABSTRACT Gassericin A is a circular bacteriocin produced by Lactobacillus gasseri strain LA39. We found a 33,333-bp plasmid, designated pLgLA39, in this strain. pLgLA39 contained 44 open reading frames, including seven genes related to gassericin A production/immunity (gaa), as well as genes for replication, plasmid maintenance, and conjugative transfer. pLgLA39 was transferred from LA39 to the type strain of L. gasseri (JCM 1131) by filter mating. The transconjugant exhibited >30-fold-higher more resistance to gassericin A and produced antibacterial activity. Lactobacillus reuteri LA6, the producer of reutericin 6, was proved to harbor a plasmid indistinguishable from pLgLA39 and carrying seven genes 100% identical to gaa. This suggests that pLgLA39 might have been transferred naturally between L. gasseri LA39 and L. reuteri LA6. The seven gaa genes of pLgLA39 were cloned into a plasmid vector to construct pGAA. JCM 1131T transformed with pGAA expressed antibacterial activity and resistance to gassericin A. pGAA was segregationally more stable than a pGAA derivative plasmid from which gaaA was deleted and even was more stable than the vector. This suggests the occurrence of postsegregational host killing by the gaa genes. pLgLA39 carried a pemIK homolog, and segregational stabilization of a plasmid by the pLgLA39-type pemIK genes was also confirmed. Thus, pLgLA39 was proved to carry the genes for at least two plasmid maintenance mechanisms, i.e., gaa and pemIK. Plasmids containing a repA gene similar to pLgLA39 repA were distributed in several L. gasseri strains.

scholarly journals DNA Sequencing and Homologous Expression of a Small Peptide Conferring Immunity to Gassericin A, a Circular Bacteriocin Produced by Lactobacillus gasseri LA39

2008 ◽  
Vol 75 (5) ◽  
pp. 1324-1330 ◽  
Author(s):  
Yasushi Kawai ◽  
Joni Kusnadi ◽  
Rober Kemperman ◽  
Jan Kok ◽  
Yoshiyuki Ito ◽  
...  
Keyword(s):  
Open Reading Frames ◽  
Transmembrane Segment ◽  
Small Peptide ◽  
Lactobacillus Gasseri ◽  
Homologous Expression ◽  
Hydrophobic Peptide ◽  
Circular Bacteriocin ◽  
Bacteriocin Gene ◽  
Reading Frames ◽  
Positively Charged

ABSTRACT Gassericin A, produced by Lactobacillus gasseri LA39, is a hydrophobic circular bacteriocin. The DNA region surrounding the gassericin A structural gene, gaaA, was sequenced, and seven open reading frames (ORFs) of 3.5 kbp (gaaBCADITE) were found with possible functions in gassericin A production, secretion, and immunity. The deduced products of the five consecutive ORFs gaaADITE have homology to those of genes involved in butyrivibriocin AR10 production, although the genetic arrangements are different in the two circular bacteriocin genes. GaaI is a small, positively charged hydrophobic peptide of 53 amino acids containing a putative transmembrane segment. Heterologous expression and homologous expression of GaaI in Lactococcus lactis subsp. cremoris MG1363 and L. gasseri JCM1131T, respectively, were studied. GaaI-expressing strains exhibited at least sevenfold-higher resistance to gassericin A than corresponding control strains, indicating that gaaI encodes an immunity peptide for gassericin A. Comparison of GaaI to peptides with similar characteristics found in the circular bacteriocin gene loci is discussed.

scholarly journals Lactobacillus reuteri BM53-1 Produces a Compound That Inhibits Sticky Glucan Synthesis by Streptococcus mutans

2021 ◽  
Vol 9 (7) ◽  
pp. 1390
Author(s):  
Masafumi Noda ◽  
Naho Sugihara ◽  
Yoshimi Sugimoto ◽  
Ikue Hayashi ◽  
Sachiko Sugimoto ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Lactic Acid ◽  
Dental Caries ◽  
Lactobacillus Reuteri ◽  
Early Stage ◽  
Pcr Analysis ◽  
Cariogenic Bacteria ◽  
Qrt Pcr ◽  
Actinidia Polygama ◽  
Glucan Synthesis

Cariogenic bacteria, such as Streptococcus (S.) mutans and S. sobrinus, produce insoluble and sticky glucans as a biofilm material. The present study demonstrates that a lactic acid bacterium (LAB) named BM53-1 produces a substance that inhibits the sticky glucan synthesis. The BM53-1 strain was isolated from a flower of Actinidia polygama and identified as Lactobacillus reuteri. The substance that inhibits sticky glucan synthesis does not exhibit antibacterial activity against S. mutans. The cariogenic S. mutans produces glucans under the control of three glucosyltransferase (GTF) enzymes, named GtfB, GtfC, and GtfD. Although GtfB and GtfC produce insoluble glucans, GtfD forms soluble glucans. Through quantitative reverse-transcriptional (qRT)-PCR analysis, it was revealed that the BM53-1-derived glucan-production inhibitor (GI) enhances the transcriptions of gtfB and gtfC genes 2- to 7-fold at the early stage of cultivation. However, that of gtfD was not enhanced in the presence of the GI, indicating that the glucan stickiness produced by S. mutans was significantly weaker in the presence of the GI. Our result demonstrates that Lb. reuteri BM53-1 is useful to prevent dental caries.

scholarly journals Microbiome-Metabolomics Reveals Prebiotic Benefits of Fucoidan Supplementation in Mice

2021 ◽  
Vol 9 (5) ◽  
pp. 505
Author(s):  
Jingyi Yuan ◽  
Song Qin ◽  
Wenjun Li ◽  
Yubing Zhang ◽  
Yuting Wang ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Triglyceride Level ◽  
Lactobacillus Reuteri ◽  
Binding Protein ◽  
Serum Triglyceride ◽  
Serum Triglyceride Level ◽  
Lipopolysaccharide Binding Protein ◽  
Lactobacillus Gasseri ◽  
Lactobacillus Animalis ◽  
Lipopolysaccharide Binding

Fucoidan is a kind of polysaccharide with antitumor and antioxidant properties, which is mainly isolated from brown algae. Although there are many reports about the prebiotic effects of polysaccharides on hosts, there are few reports about the effects of fucoidan on blood biochemical indexes, intestinal microbiome, and metabolic function on healthy hosts. We applied 16S rRNA gene amplicon sequencing and LC-MS/MS metabolomics to evaluate the changes in the gut microbiome and metabolite profiles of fucoidan treatment in mice over 10 weeks. Fucoidan treatment modulated lipid metabolism, including significantly decreasing serum triglyceride level in healthy mice. Fucoidan also significantly inhibited serum lipopolysaccharide-binding protein (LBP) concentration, a biomarker of endotoxemia. Correlation analysis further showed that Lactobacillus animalis populations that were enriched by fucoidan demonstrated significantly negative correlations with serum triglyceride level. The abundance of Lactobacillus gasseri and Lactobacillus reuteri, increased by fucoidan supplementation, demonstrated significantly negative correlation with lipopolysaccharide-binding protein levels. Lactobacillus gasseri also demonstrated significantly positive correlations with three tryptophan-related metabolites, including indoleacrylic acid, 3-indoleacrylic acid, and 5-hydroxytryptamine, which were all increased by fucoidan administration. Combined with the previous evidence, the results indicate that fucoidan exerts prebiotic effects, such as lipid metabolism suppression and metabolic endotoxemia suppression, by modulating the abundance of gut microbiota, such as Lactobacillus animalis, Lactobacillus gasseri, and Lactobacillus reuteri, as well as microbiota-dependent metabolites, such as tryptophan-related metabolites.

scholarly journals Vaccinia Virus F13L Protein with a Conserved Phospholipase Catalytic Motif Induces Colocalization of the B5R Envelope Glycoprotein in Post-Golgi Vesicles

2001 ◽  
Vol 75 (16) ◽  
pp. 7528-7542 ◽  
Author(s):  
Matloob Husain ◽  
Bernard Moss
Keyword(s):  
Vaccinia Virus ◽  
Fluorescent Protein ◽  
Plasmid Vector ◽  
Recombinant Vaccinia Virus ◽  
Open Reading Frames ◽  
Type I ◽  
Golgi Vesicles ◽  
Infected Cells ◽  
Catalytic Motif ◽  
Green Fluorescent

ABSTRACT The wrapping of intracellular mature vaccinia virions by modifiedtrans-Golgi or endosomal cisternae to form intracellular enveloped virions is dependent on at least two viral proteins encoded by the B5R and F13L open reading frames. B5R is a type I integral membrane glycoprotein, whereas F13L is an unglycosylated, palmitylated protein with a motif that is conserved in a superfamily of phospholipid-metabolizing enzymes. Microscopic visualization of the F13L protein was achieved by fusing it to the enhanced green fluorescent protein (GFP). F13L-GFP was functional when expressed by a recombinant vaccinia virus in which it replaced the wild-type F13L gene or by transfection of uninfected cells with a plasmid vector followed by infection with an F13L deletion mutant. In uninfected or infected cells, F13L-GFP was associated with Golgi cisternae and post-Golgi vesicles containing the LAMP 2 late endosomal-lysosomal marker. Association of F13L-GFP with vesicles was dependent on an intact phospholipase catalytic motif and sites of palmitylation. The B5R protein was also associated with LAMP2-containing vesicles when F13L-GFP was coexpressed, but was largely restricted to Golgi cisternae in the absence of F13L-GFP or when the F13L moiety was mutated. We suggest that the F13L protein, like its human phospholipase D homolog, regulates vesicle formation and that this process is involved in intracellular enveloped virion membrane formation.

scholarly journals Transposase-Mediated Excision, Conjugative Transfer, and Diversity of ICE6013 Elements in Staphylococcus aureus

2017 ◽  
Vol 199 (8) ◽  
Author(s):  
Emily A. Sansevere ◽  
Xiao Luo ◽  
Joo Youn Park ◽  
Sunghyun Yoon ◽  
Keun Seok Seo ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Sequence Analysis ◽  
Integration Site ◽  
Consensus Sequence ◽  
Open Reading Frames ◽  
Conjugative Plasmid ◽  
Site Preference ◽  
Conjugative Transfer ◽  
Content Type ◽  
Integrative Conjugative Elements

ABSTRACT ICE6013 represents one of two families of integrative conjugative elements (ICEs) identified in the pan-genome of the human and animal pathogen Staphylococcus aureus. Here we investigated the excision and conjugation functions of ICE6013 and further characterized the diversity of this element. ICE6013 excision was not significantly affected by growth, temperature, pH, or UV exposure and did not depend on recA. The IS30-like DDE transposase (Tpase; encoded by orf1 and orf2) of ICE6013 must be uninterrupted for excision to occur, whereas disrupting three of the other open reading frames (ORFs) on the element significantly affects the level of excision. We demonstrate that ICE6013 conjugatively transfers to different S. aureus backgrounds at frequencies approaching that of the conjugative plasmid pGO1. We found that excision is required for conjugation, that not all S. aureus backgrounds are successful recipients, and that transconjugants acquire the ability to transfer ICE6013. Sequencing of chromosomal integration sites in serially passaged transconjugants revealed a significant integration site preference for a 15-bp AT-rich palindromic consensus sequence, which surrounds the 3-bp target site that is duplicated upon integration. A sequence analysis of ICE6013 from different host strains of S. aureus and from eight other species of staphylococci identified seven divergent subfamilies of ICE6013 that include sequences previously classified as a transposon, a plasmid, and various ICEs. In summary, these results indicate that the IS30-like Tpase functions as the ICE6013 recombinase and that ICE6013 represents a diverse family of mobile genetic elements that mediate conjugation in staphylococci. IMPORTANCE Integrative conjugative elements (ICEs) encode the abilities to integrate into and excise from bacterial chromosomes and plasmids and mediate conjugation between bacteria. As agents of horizontal gene transfer, ICEs may affect bacterial evolution. ICE6013 represents one of two known families of ICEs in the pathogen Staphylococcus aureus, but its core functions of excision and conjugation are not well studied. Here, we show that ICE6013 depends on its IS30-like DDE transposase for excision, which is unique among ICEs, and we demonstrate the conjugative transfer and integration site preference of ICE6013. A sequence analysis revealed that ICE6013 has diverged into seven subfamilies that are dispersed among staphylococci.

Multiple mechanisms for expression of incompatibility by broad-host-range plasmid RK2

1982 ◽  
Vol 152 (3) ◽  
pp. 1078-1090
Author(s):  
R Meyer ◽  
M Hinds
Keyword(s):  
Dna Replication ◽  
Host Range ◽  
Plasmid Dna ◽  
Plasmid Vector ◽  
Broad Host Range ◽  
Plasmid Maintenance ◽  
Broad Host Range Plasmid ◽  
Expression Of Genes ◽  
Plasmid Partitioning ◽  
Plasmid Rk2

By cloning fragments of plasmid DNA, we have shown that RK2 expresses incompatibility by more than one mechanism. One previously identified (R. J. Meyer, Mol. Gen, Genet. 177:155--161, 1979; Thomas et al., Mol. Gen. Genet. 181:1--7, 1981) determinant for incompatibility is linked to the origin of plasmid DNA replication. When cloned into a plasmid vector, this determinant prevents the stable inheritance of a coresident RK2. However, susceptibility to this mechanism of incompatibility requires an active RK2 replicon and is abolished if another replicator is provided. We have also cloned a second incompatibility determinant, encoded within the 54.1- to 56.4-kilobase region of RK2 DNA, which we call IncP-1(II). An RK2 derivative remains sensitive to IncP-1(II), even when it is not replicating by means of the RK2 replicon. The 54.1- to 56.4-kilobase DNA does not confer susceptibility to the IncP-1(II) mechanism, nor does it encode a detectable system for efficient plasmid partitioning. The incompatibility may be related to the expression of genes mapping in the 54.1- to 56.4-kilobase region, which are required for plasmid maintenance and suppression of plasmid-encoded killing functions.

scholarly journals Genetic Determinants of Reutericyclin Biosynthesis in Lactobacillus reuteri

2015 ◽  
Vol 81 (6) ◽  
pp. 2032-2041 ◽  
Author(s):  
Xiaoxi B. Lin ◽  
Christopher T. Lohans ◽  
Rebbeca Duar ◽  
Jinshui Zheng ◽  
John C. Vederas ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Genomic Island ◽  
Lactobacillus Reuteri ◽  
Acyl Carrier Protein ◽  
Open Reading Frames ◽  
Protein Domain ◽  
Regulatory Proteins ◽  
Tetramic Acid ◽  
Genetic Determinants ◽  
Content Type

ABSTRACTReutericyclin is a unique antimicrobial tetramic acid produced by some strains ofLactobacillus reuteri. This study aimed to identify the genetic determinants of reutericyclin biosynthesis. Comparisons of the genomes of reutericyclin-producingL. reuteristrains with those of non-reutericyclin-producing strains identified a genomic island of 14 open reading frames (ORFs) including genes coding for a nonribosomal peptide synthetase (NRPS), a polyketide synthase (PKS), homologues of PhlA, PhlB, and PhlC, and putative transport and regulatory proteins. The protein encoded byrtcNis composed of a condensation domain, an adenylation domain likely specific ford-leucine, and a thiolation domain.rtcKcodes for a PKS that is composed of a ketosynthase domain, an acyl-carrier protein domain, and a thioesterase domain. The products ofrtcA,rtcB, andrtcCare homologous to the diacetylphloroglucinol-biosynthetic proteins PhlABC and may acetylate the tetramic acid moiety produced by RtcN and RtcK, forming reutericyclin. Deletion ofrtcNorrtcABCinL. reuteriTMW1.656 abrogated reutericyclin production but did not affect resistance to reutericyclin. Genes coding for transport and regulatory proteins could be deleted only in the reutericyclin-negativeL. reuteristrain TMW1.656ΔrtcN, and these deletions eliminated reutericyclin resistance. The genomic analyses suggest that the reutericyclin genomic island was horizontally acquired from an unknown source during a unique event. The combination of PhlABC homologues with both an NRPS and a PKS has also been identified in the lactic acid bacteriaStreptococcus mutansandLactobacillus plantarum, suggesting that the genes in these organisms and those inL. reuterishare an evolutionary origin.

Survival of Pseudomonas fluorescens containing plasmids RP4 or pRK2501 and plasmid stability after introduction into two soils of different texture

1989 ◽  
Vol 35 (10) ◽  
pp. 951-959 ◽  
Author(s):  
J. D. Van Elsas ◽  
J. T. Trevors ◽  
L. S. Van Overbeek ◽  
M. E. Starodub
Keyword(s):  
Pseudomonas Fluorescens ◽  
Plasmid Stability ◽  
Loamy Sand ◽  
Conjugative Plasmid ◽  
Detectable Effect ◽  
Wheat Roots ◽  
Soil Extracts ◽  
Plasmid Maintenance ◽  
Plasmid Loss ◽  
Introduced Populations

Survival of Pseudomonas fluorescens R2f containing either the conjugative plasmid RP4 or the nonconjugative plasmid pRK2501, and stability of the plasmids were studied in two soils, Ede loamy sand and Guelph loam, and in extracts prepared from these soils. In sterile soils, the introduced bacterial populations initially increased and then remained stable over a 47-day period. The presence of wheat roots did not significantly influence bacterial numbers in Guelph loam, whereas a slight increase occurred in Ede loamy sand. In Guelph loam, both plasmids were stably maintained in the introduced populations, but in Ede loamy sand substantial plasmid loss was observed. The presence of added phosphate in Ede loamy sand enhanced plasmid maintenance in the introduced R2f population. In nonsterile Guelph loam, a slow decline in the introduced populations was noted, regardless of plasmid type, whereas in Ede loamy sand the decline was more rapid. There was no detectable effect of plasmid type on host survival. Both plasmids RP4 and pRK2501 remained present in the R2f populations in these soils. The results obtained with sterile soil extracts substantiated the data on plasmid loss in both soils; both plasmids were rather unstable during starvation in minimal medium. The results indicated the absence of an effect of plasmid type on host survival. Soil type significantly affected host survival and plasmid maintenance, and higher survival and stability were observed in the heavier-textured Guelph loam.Key words: survival, plasmid stability, Pseudomonas spp., soil, microcosms.

scholarly journals Complete Nucleotide Sequence of Plasmid Rts1: Implications for Evolution of Large Plasmid Genomes

2002 ◽  
Vol 184 (12) ◽  
pp. 3194-3202 ◽  
Author(s):  
Takahiro Murata ◽  
Makoto Ohnishi ◽  
Takeshi Ara ◽  
Jun Kaneko ◽  
Chang-Gyun Han ◽  
...  
Keyword(s):  
Nucleotide Sequence ◽  
Complete Nucleotide Sequence ◽  
Sequence Similarity ◽  
Open Reading Frames ◽  
Conjugative Plasmid ◽  
Proteus Vulgaris ◽  
Significant Sequence Similarity ◽  
Modular Evolution ◽  
Broad Array ◽  
Reading Frames

ABSTRACT Rts1, a large conjugative plasmid originally isolated from Proteus vulgaris, is a prototype for the IncT plasmids and exhibits pleiotropic thermosensitive phenotypes. Here we report the complete nucleotide sequence of Rts1. The genome is 217,182 bp in length and contains 300 potential open reading frames (ORFs). Among these, the products of 141 ORFs, including 9 previously identified genes, displayed significant sequence similarity to known proteins. The set of genes responsible for the conjugation function of Rts1 has been identified. A broad array of genes related to diverse processes of DNA metabolism were also identified. Of particular interest was the presence of tus-like genes that could be involved in replication termination. Inspection of the overall genome organization revealed that the Rts1 genome is composed of four large modules, providing an example of modular evolution of plasmid genomes.

scholarly journals The Maltose ABC Transporter in Lactococcus lactis Facilitates High-Level Sensitivity to the Circular Bacteriocin Garvicin ML

2012 ◽  
Vol 56 (6) ◽  
pp. 2908-2915 ◽  
Author(s):  
Christina Gabrielsen ◽  
Dag A. Brede ◽  
Pablo E. Hernández ◽  
Ingolf F. Nes ◽  
Dzung B. Diep
Keyword(s):  
Lactococcus Lactis ◽  
Abc Transporter ◽  
Specific Protein ◽  
Open Reading Frames ◽  
Content Type ◽  
Circular Bacteriocin ◽  
Carbohydrate Fermentation ◽  
High Level ◽  
Normal Sensitivity ◽  
Maltose Abc Transporter

ABSTRACTWe generated and characterized a series of spontaneous mutants ofLactococcus lactisIL1403 with average 6- to 11-fold-lowered sensitivities to the circular bacteriocin garvicin ML (GarML). Carbohydrate fermentation assays highlighted changes in carbohydrate metabolism, specifically loss of the ability to metabolize starch and maltose, in these mutants. PCR and sequencing showed that a 13.5-kb chromosomal deletion encompassing 12 open reading frames, mainly involved in starch and maltose utilization, had spontaneously occurred in the GarML-resistant mutants. Growth experiments revealed a correlation between sensitivity to GarML and carbon catabolite repression (CCR); i.e., sensitivity to GarML increased significantly when wild-type cells were grown on maltose and galactose as sole carbohydrates, an effect which was alleviated by the presence of glucose. Among the genes deleted in the mutants weremalEFG, which encode a CCR-regulated membrane-bound maltose ABC transporter. The complementation of mutants with these three genes recovered normal sensitivity to the bacteriocin, suggesting an essential role of the maltose ABC transporter in the antimicrobial activity of GarML. This notion was supported by the fact that the level of sensitivity to GarML was dose dependent, increasing with higher expression levels ofmalEFGover a 50-fold range. To our knowledge, this is the first time a specific protein complex has been demonstrated to be involved in sensitivity to a circular bacteriocin.

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