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The extended regulatory networks of SXT/R391 integrative and conjugative elements and IncA/C conjugative plasmids.

Poulin-Laprade D, Carraro N, Burrus V - Front Microbiol (2015)

Bottom Line: Recently, the transcriptional regulators that govern their dissemination through the expression of ICE- or plasmid-encoded transfer genes have been described.Unrelated repressors control the activation of conjugation by preventing the expression of two related master activator complexes in both types of elements, i.e., SetCD in SXT/R391 ICEs and AcaCD in IncA/C plasmids.Finally, in addition to activating ICE- or plasmid-borne genes, these master activators have been shown to specifically activate phylogenetically unrelated mobilizable genomic islands (MGIs) that also disseminate antibiotic resistance genes and other adaptive traits among a plethora of pathogens such as Vibrio cholerae and Salmonella enterica.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Bacterial Molecular Genetics, Département de Biologie, Faculté des Sciences, Université de Sherbrooke , Sherbrooke, QC, Canada.

ABSTRACT
Nowadays, healthcare systems are challenged by a major worldwide drug resistance crisis caused by the massive and rapid dissemination of antibiotic resistance genes and associated emergence of multidrug resistant pathogenic bacteria, in both clinical and environmental settings. Conjugation is the main driving force of gene transfer among microorganisms. This mechanism of horizontal gene transfer mediates the translocation of large DNA fragments between two bacterial cells in direct contact. Integrative and conjugative elements (ICEs) of the SXT/R391 family (SRIs) and IncA/C conjugative plasmids (ACPs) are responsible for the dissemination of a broad spectrum of antibiotic resistance genes among diverse species of Enterobacteriaceae and Vibrionaceae. The biology, diversity, prevalence and distribution of these two families of conjugative elements have been the subject of extensive studies for the past 15 years. Recently, the transcriptional regulators that govern their dissemination through the expression of ICE- or plasmid-encoded transfer genes have been described. Unrelated repressors control the activation of conjugation by preventing the expression of two related master activator complexes in both types of elements, i.e., SetCD in SXT/R391 ICEs and AcaCD in IncA/C plasmids. Finally, in addition to activating ICE- or plasmid-borne genes, these master activators have been shown to specifically activate phylogenetically unrelated mobilizable genomic islands (MGIs) that also disseminate antibiotic resistance genes and other adaptive traits among a plethora of pathogens such as Vibrio cholerae and Salmonella enterica.

No MeSH data available.


Related in: MedlinePlus

Comparison of the regulatory modules of SXT/R391 ICEs (SRI) and IncA/C plasmids (ACP). The genes are color-coded as indicated in Figure 1 legend. Numbers between the elements represent the percentage of identity between orthologous proteins. The regulation exerted by SetR, Acr1, and Acr2 is indicated (minus sign for repression, plus sign for activation). For clarity, ORF names s0XX were shortened as XX for SRI and vcrxXXX as XXX for ACP.
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Figure 2: Comparison of the regulatory modules of SXT/R391 ICEs (SRI) and IncA/C plasmids (ACP). The genes are color-coded as indicated in Figure 1 legend. Numbers between the elements represent the percentage of identity between orthologous proteins. The regulation exerted by SetR, Acr1, and Acr2 is indicated (minus sign for repression, plus sign for activation). For clarity, ORF names s0XX were shortened as XX for SRI and vcrxXXX as XXX for ACP.

Mentions: SRIs and ACPs bear distinct regulatory modules that govern their self-transmissibility (Figure 2). These regulatory modules code for unrelated repressors: SetR for SRIs and Acr1 and Acr2 for ACPs (Beaber et al., 2004; Carraro et al., 2014a). In contrast, the regulatory module of SRIs and ACPs code for related transcriptional activator complexes, respectively SetCD and AcaCD, that drive the expression of the conjugative genes and other functions (Beaber et al., 2002b; Carraro et al., 2014a; Poulin-Laprade et al., 2015). SetCD and AcaCD are distant relatives of FlhCD, the master activator of flagellum biosynthesis in many Gram-negative bacteria (Chevance and Hughes, 2008; Fitzgerald et al., 2014). Recent studies established the AcaCD and SetCD regulons and refined the models of transcriptional organization of the functional core of both types of elements (Figure 1; Carraro et al., 2014a; Poulin-Laprade et al., 2015).


The extended regulatory networks of SXT/R391 integrative and conjugative elements and IncA/C conjugative plasmids.

Poulin-Laprade D, Carraro N, Burrus V - Front Microbiol (2015)

Comparison of the regulatory modules of SXT/R391 ICEs (SRI) and IncA/C plasmids (ACP). The genes are color-coded as indicated in Figure 1 legend. Numbers between the elements represent the percentage of identity between orthologous proteins. The regulation exerted by SetR, Acr1, and Acr2 is indicated (minus sign for repression, plus sign for activation). For clarity, ORF names s0XX were shortened as XX for SRI and vcrxXXX as XXX for ACP.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4542580&req=5

Figure 2: Comparison of the regulatory modules of SXT/R391 ICEs (SRI) and IncA/C plasmids (ACP). The genes are color-coded as indicated in Figure 1 legend. Numbers between the elements represent the percentage of identity between orthologous proteins. The regulation exerted by SetR, Acr1, and Acr2 is indicated (minus sign for repression, plus sign for activation). For clarity, ORF names s0XX were shortened as XX for SRI and vcrxXXX as XXX for ACP.
Mentions: SRIs and ACPs bear distinct regulatory modules that govern their self-transmissibility (Figure 2). These regulatory modules code for unrelated repressors: SetR for SRIs and Acr1 and Acr2 for ACPs (Beaber et al., 2004; Carraro et al., 2014a). In contrast, the regulatory module of SRIs and ACPs code for related transcriptional activator complexes, respectively SetCD and AcaCD, that drive the expression of the conjugative genes and other functions (Beaber et al., 2002b; Carraro et al., 2014a; Poulin-Laprade et al., 2015). SetCD and AcaCD are distant relatives of FlhCD, the master activator of flagellum biosynthesis in many Gram-negative bacteria (Chevance and Hughes, 2008; Fitzgerald et al., 2014). Recent studies established the AcaCD and SetCD regulons and refined the models of transcriptional organization of the functional core of both types of elements (Figure 1; Carraro et al., 2014a; Poulin-Laprade et al., 2015).

Bottom Line: Recently, the transcriptional regulators that govern their dissemination through the expression of ICE- or plasmid-encoded transfer genes have been described.Unrelated repressors control the activation of conjugation by preventing the expression of two related master activator complexes in both types of elements, i.e., SetCD in SXT/R391 ICEs and AcaCD in IncA/C plasmids.Finally, in addition to activating ICE- or plasmid-borne genes, these master activators have been shown to specifically activate phylogenetically unrelated mobilizable genomic islands (MGIs) that also disseminate antibiotic resistance genes and other adaptive traits among a plethora of pathogens such as Vibrio cholerae and Salmonella enterica.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Bacterial Molecular Genetics, Département de Biologie, Faculté des Sciences, Université de Sherbrooke , Sherbrooke, QC, Canada.

ABSTRACT
Nowadays, healthcare systems are challenged by a major worldwide drug resistance crisis caused by the massive and rapid dissemination of antibiotic resistance genes and associated emergence of multidrug resistant pathogenic bacteria, in both clinical and environmental settings. Conjugation is the main driving force of gene transfer among microorganisms. This mechanism of horizontal gene transfer mediates the translocation of large DNA fragments between two bacterial cells in direct contact. Integrative and conjugative elements (ICEs) of the SXT/R391 family (SRIs) and IncA/C conjugative plasmids (ACPs) are responsible for the dissemination of a broad spectrum of antibiotic resistance genes among diverse species of Enterobacteriaceae and Vibrionaceae. The biology, diversity, prevalence and distribution of these two families of conjugative elements have been the subject of extensive studies for the past 15 years. Recently, the transcriptional regulators that govern their dissemination through the expression of ICE- or plasmid-encoded transfer genes have been described. Unrelated repressors control the activation of conjugation by preventing the expression of two related master activator complexes in both types of elements, i.e., SetCD in SXT/R391 ICEs and AcaCD in IncA/C plasmids. Finally, in addition to activating ICE- or plasmid-borne genes, these master activators have been shown to specifically activate phylogenetically unrelated mobilizable genomic islands (MGIs) that also disseminate antibiotic resistance genes and other adaptive traits among a plethora of pathogens such as Vibrio cholerae and Salmonella enterica.

No MeSH data available.


Related in: MedlinePlus