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Identification and characterization of the chromosomal yefM-yoeB toxin-antitoxin system of Streptococcus suis.

Zheng C, Xu J, Ren S, Li J, Xia M, Chen H, Bei W - Sci Rep (2015)

Bottom Line: Overproduction of S. suis YoeB toxin inhibited the growth of E. coli, and the toxicity of S. suis YoeB could be alleviated by the antitoxin YefM from S. suis and Streptococcus pneumoniae, but not by E. coli YefM.In a murine infection model, deletion of the yefM-yoeB locus had no effect on the virulence of S. suis serotype 2.Collectively, our data suggested that the yefM-yoeB locus of S. suis is an active TA system without the involvement of virulence.

View Article: PubMed Central - PubMed

Affiliation: 1] State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China [2] Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.

ABSTRACT
Toxin-antitoxin (TA) systems are widely prevalent in the genomes of bacteria and archaea. These modules have been identified in Escherichia coli and various other bacteria. However, their presence in the genome of Streptococcus suis, an important zoonotic pathogen, has received little attention. In this study, we describe the identification and characterization of a type II TA system, comprising the chromosomal yefM-yoeB locus of S. suis. The yefM-yoeB locus is present in the genome of most serotypes of S. suis. Overproduction of S. suis YoeB toxin inhibited the growth of E. coli, and the toxicity of S. suis YoeB could be alleviated by the antitoxin YefM from S. suis and Streptococcus pneumoniae, but not by E. coli YefM. More importantly, introduction of the S. suis yefM-yoeB system into E. coli could affect cell growth. In a murine infection model, deletion of the yefM-yoeB locus had no effect on the virulence of S. suis serotype 2. Collectively, our data suggested that the yefM-yoeB locus of S. suis is an active TA system without the involvement of virulence.

No MeSH data available.


Related in: MedlinePlus

Toxicity of YoeBSsu can be alleviated by YefMSsu and YefMSpn, but not by YefMEco.E. coli BL21(DE3) cells harbouring the respective selective expression plasmids were grown to an OD600 of about 0.3. Each culture was then divided into four equal parts, to three of which were individually added 0.2% L-arabinose, 1 mM IPTG or both, respectively. The fourth part served as the control, to which nothing was added. These cultures were further incubated and samples were taken every hour to determine the OD600. (a) Schematic representation of plasmids for the selective expression of YefM and YoeB under the control of PBAD and Plac, respectively. (b) Toxicity of YoeBSsu can be alleviated by YefMSsu. (c) Toxicity of YoeBSsu can be alleviated by YefMSpn. (d) Toxicity of YoeBSsu cannot be alleviated by YefMEco. The data shown are averages with standard deviations for the results from three independent experiments.
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f4: Toxicity of YoeBSsu can be alleviated by YefMSsu and YefMSpn, but not by YefMEco.E. coli BL21(DE3) cells harbouring the respective selective expression plasmids were grown to an OD600 of about 0.3. Each culture was then divided into four equal parts, to three of which were individually added 0.2% L-arabinose, 1 mM IPTG or both, respectively. The fourth part served as the control, to which nothing was added. These cultures were further incubated and samples were taken every hour to determine the OD600. (a) Schematic representation of plasmids for the selective expression of YefM and YoeB under the control of PBAD and Plac, respectively. (b) Toxicity of YoeBSsu can be alleviated by YefMSsu. (c) Toxicity of YoeBSsu can be alleviated by YefMSpn. (d) Toxicity of YoeBSsu cannot be alleviated by YefMEco. The data shown are averages with standard deviations for the results from three independent experiments.

Mentions: We further investigated the toxic and antitoxic effect of the TA components using the selective expression system constructed here. In the selective expression plasmid, the IPTG-inducible promoter Plac and the arabinose-inducible promoter PBAD control the expression of YefM and YoeB, respectively (Fig. 4a). Thus, E. coli BL21 (DE3) cells harbouring the pETBAD-yefMSsu-yoeB plasmid could express the S. suis YefM and/or YoeB upon induction with IPTG and/or L-arabinose. As shown in Fig. 4b, the E. coli BL21 (DE3) cells exhibited considerable growth inhibition in the presence of L-arabinose. In contrast, only moderate growth inhibition was observed in the presence of IPTG or IPTG and L-arabinose together.


Identification and characterization of the chromosomal yefM-yoeB toxin-antitoxin system of Streptococcus suis.

Zheng C, Xu J, Ren S, Li J, Xia M, Chen H, Bei W - Sci Rep (2015)

Toxicity of YoeBSsu can be alleviated by YefMSsu and YefMSpn, but not by YefMEco.E. coli BL21(DE3) cells harbouring the respective selective expression plasmids were grown to an OD600 of about 0.3. Each culture was then divided into four equal parts, to three of which were individually added 0.2% L-arabinose, 1 mM IPTG or both, respectively. The fourth part served as the control, to which nothing was added. These cultures were further incubated and samples were taken every hour to determine the OD600. (a) Schematic representation of plasmids for the selective expression of YefM and YoeB under the control of PBAD and Plac, respectively. (b) Toxicity of YoeBSsu can be alleviated by YefMSsu. (c) Toxicity of YoeBSsu can be alleviated by YefMSpn. (d) Toxicity of YoeBSsu cannot be alleviated by YefMEco. The data shown are averages with standard deviations for the results from three independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4536659&req=5

f4: Toxicity of YoeBSsu can be alleviated by YefMSsu and YefMSpn, but not by YefMEco.E. coli BL21(DE3) cells harbouring the respective selective expression plasmids were grown to an OD600 of about 0.3. Each culture was then divided into four equal parts, to three of which were individually added 0.2% L-arabinose, 1 mM IPTG or both, respectively. The fourth part served as the control, to which nothing was added. These cultures were further incubated and samples were taken every hour to determine the OD600. (a) Schematic representation of plasmids for the selective expression of YefM and YoeB under the control of PBAD and Plac, respectively. (b) Toxicity of YoeBSsu can be alleviated by YefMSsu. (c) Toxicity of YoeBSsu can be alleviated by YefMSpn. (d) Toxicity of YoeBSsu cannot be alleviated by YefMEco. The data shown are averages with standard deviations for the results from three independent experiments.
Mentions: We further investigated the toxic and antitoxic effect of the TA components using the selective expression system constructed here. In the selective expression plasmid, the IPTG-inducible promoter Plac and the arabinose-inducible promoter PBAD control the expression of YefM and YoeB, respectively (Fig. 4a). Thus, E. coli BL21 (DE3) cells harbouring the pETBAD-yefMSsu-yoeB plasmid could express the S. suis YefM and/or YoeB upon induction with IPTG and/or L-arabinose. As shown in Fig. 4b, the E. coli BL21 (DE3) cells exhibited considerable growth inhibition in the presence of L-arabinose. In contrast, only moderate growth inhibition was observed in the presence of IPTG or IPTG and L-arabinose together.

Bottom Line: Overproduction of S. suis YoeB toxin inhibited the growth of E. coli, and the toxicity of S. suis YoeB could be alleviated by the antitoxin YefM from S. suis and Streptococcus pneumoniae, but not by E. coli YefM.In a murine infection model, deletion of the yefM-yoeB locus had no effect on the virulence of S. suis serotype 2.Collectively, our data suggested that the yefM-yoeB locus of S. suis is an active TA system without the involvement of virulence.

View Article: PubMed Central - PubMed

Affiliation: 1] State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China [2] Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.

ABSTRACT
Toxin-antitoxin (TA) systems are widely prevalent in the genomes of bacteria and archaea. These modules have been identified in Escherichia coli and various other bacteria. However, their presence in the genome of Streptococcus suis, an important zoonotic pathogen, has received little attention. In this study, we describe the identification and characterization of a type II TA system, comprising the chromosomal yefM-yoeB locus of S. suis. The yefM-yoeB locus is present in the genome of most serotypes of S. suis. Overproduction of S. suis YoeB toxin inhibited the growth of E. coli, and the toxicity of S. suis YoeB could be alleviated by the antitoxin YefM from S. suis and Streptococcus pneumoniae, but not by E. coli YefM. More importantly, introduction of the S. suis yefM-yoeB system into E. coli could affect cell growth. In a murine infection model, deletion of the yefM-yoeB locus had no effect on the virulence of S. suis serotype 2. Collectively, our data suggested that the yefM-yoeB locus of S. suis is an active TA system without the involvement of virulence.

No MeSH data available.


Related in: MedlinePlus