The Bifunctional Cell Wall Hydrolase CwlT Is Needed for Conjugation of the Integrative and Conjugative Element ICE<i>Bs1</i>in Bacillus subtilis and B. anthracis

DeWitt, Tyler; Grossman, Alan D.

doi:10.1128/jb.00012-14

Cited by 42 publications

(35 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, disruption of ICE6013 orf5 to orf8 and orf12 affected conjugation, as expected from previous studies showing that their homologs were required for the conjugation of ICEBs1 (39,(44)(45)(46). Our results provided no evidence for the mobilization of sequences flanking the element's integration site.…”

Section: Discussionsupporting

confidence: 31%

Transposase-Mediated Excision, Conjugative Transfer, and Diversity of ICE 6013 Elements in Staphylococcus aureus

et al. 2017

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionsupporting

confidence: 31%

Transposase-Mediated Excision, Conjugative Transfer, and Diversity of ICE 6013 Elements in Staphylococcus aureus

et al. 2017

View full text Add to dashboard Cite

show abstract

“…This could also be through inhibition of a component of the machinery. Transfer of DNA through the ICEBs1-encoded conjugation machinery depends on CwlT (46), a secreted cell wall hydrolase encoded by ICEBs1 (46,47). Components of the cell envelope, including lipoteichoic acids (35,36), wall teichoic acids (37,38), and the phospholipids cardiolipin (36), phosphatidylglycerol (39), and lysyl-phosphatidylglycerol (36,40), can modulate the function of at least some cell wall hydrolases.…”

Section: Discussionmentioning

confidence: 99%

The Composition of the Cell Envelope Affects Conjugation in Bacillus subtilis

Johnson

Grossman

2016

J Bacteriol

Self Cite

View full text Add to dashboard Cite

Conjugation in bacteria is the contact-dependent transfer of DNA from one cell to another via donor-encoded conjugation machinery. It is a major type of horizontal gene transfer between bacteria. Conjugation of the integrative and conjugative element ICEBs1 into Bacillus subtilis is affected by the composition of phospholipids in the cell membranes of the donor and recipient. We found that reduction (or elimination) of lysyl-phosphatidylglycerol caused by loss of mprF caused a decrease in conjugation efficiency. Conversely, alterations that caused an increase in lysyl-phosphatidylglycerol, including loss of ugtP or overproduction of mprF, caused an increase in conjugation efficiency. In addition, we found that mutations that alter production of other phospholipids, e.g., loss of clsA and yfnI, also affected conjugation, apparently without substantively altering levels of lysyl-phosphatidylglycerol, indicating that there are multiple pathways by which changes to the cell envelope affect conjugation. We found that the contribution of mprF to conjugation was affected by the chemical environment. Wild-type cells were generally more responsive to addition of anions that enhanced conjugation, whereas mprF mutant cells were more sensitive to combinations of anions that inhibited conjugation at pH 7. Our results indicate that mprF and lysyl-phosphatidylglycerol allow cells to maintain relatively consistent conjugation efficiencies under a variety of ionic conditions. IMPORTANCEHorizontal gene transfer is a driving force in microbial evolution, enabling cells that receive DNA to acquire new genes and phenotypes. Conjugation, the contact-dependent transfer of DNA from a donor to a recipient by a donor-encoded secretion machine, is a prevalent type of horizontal gene transfer. Although critically important, it is not well understood how the recipient influences the success of conjugation. We found that the composition of phospholipids in the membranes of donors and recipients influences the success of transfer of the integrative and conjugative element ICEBs1 in Bacillus subtilis. Specifically, the presence of lysyl-phosphatidylglycerol enables relatively constant conjugation efficiencies in a range of diverse chemical environments.

show abstract

“…cwlT encodes a bifunctional murein hydrolase that contains a muramidase and a DL-endopeptidase domain (84). The N-acetylmuramidase domain of CwlT is necessary for the conjugation of ICEBs1 as it is implicated in cellwall processing prior to the assembly of the T4SS (85). The peptidase domain of CwlT is not essential, but it enhances ICEBs1 conjugative transfer.…”

Section: Conjugative Transfermentioning

confidence: 99%

Biology of Three ICE Families: SXT/R391, ICE Bs1 , and ICE St1 /ICE St3

Carraro

Burrus

2014

Microbiol Spectr

View full text Add to dashboard Cite

Integrative and Conjugative Elements (ICEs) are bacterial mobile genetic elements that play a key role in bacterial genomes dynamics and evolution. ICEs are widely distributed among virtually all bacterial genera. Recent extensive studies have unraveled their high diversity and complexity. The present review depicts the general conserved features of ICEs and describes more precisely three major families of ICEs that have been extensively studied in the past decade for their biology, their evolution and their impact on genomes dynamics. First, the large SXT/R391 family of ICEs disseminates antibiotic resistance genes and drives the exchange of mobilizable genomic islands (MGIs) between many enteric pathogens such as Vibrio cholerae. Second, ICEBs1 of Bacillus subtilis is the most well understood ICE of Gram-positive bacteria, notably regarding the regulation of its dissemination and its initially unforeseen extrachromosomal replication, which could be a common feature of ICEs of both Gram-positive and Gram-negative bacteria. Finally, ICESt1 and ICESt3 of Streptococcus thermophilus are the prototypes of a large family of ICEs widely distributed among various streptococci. These ICEs carry an original regulation module that associates regulators related to those of both SXT/R391 and ICEBs1. Study of ICESt1 and ICESt3 uncovered the cis-mobilization of related genomic islands (CIMEs) by a mechanism called accretion-mobilization, which likely represents a paradigm for the evolution of many ICEs and genomic islands. These three major families of ICEs give a glimpse about ICEs dynamics and their high impact on bacterial adaptation.

show abstract

The Bifunctional Cell Wall Hydrolase CwlT Is Needed for Conjugation of the Integrative and Conjugative Element ICEBs1in Bacillus subtilis and B. anthracis

Cited by 42 publications

References 54 publications

Transposase-Mediated Excision, Conjugative Transfer, and Diversity of ICE 6013 Elements in Staphylococcus aureus

Transposase-Mediated Excision, Conjugative Transfer, and Diversity of ICE 6013 Elements in Staphylococcus aureus

The Composition of the Cell Envelope Affects Conjugation in Bacillus subtilis

Biology of Three ICE Families: SXT/R391, ICE Bs1 , and ICE St1 /ICE St3

Contact Info

Product

Resources

About