A
            <i>Bacteroides</i>
            Conjugative Transposon, CTnERL, Can Transfer a Portion of Itself by Conjugation without Excising from the Chromosome

Whittle, Gabrielle; Hamburger, Nathan; Shoemaker, Nadja B.; Salyers, Abigail A.

doi:10.1128/jb.188.3.1169-1174.2006

Cited by 21 publications

(22 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, a recent study characterizing the Mob proteins on the CTn341 CTnDOT-related element suggested that the oriT of CTn341 was just upstream of mobA. The previous studies that localized the CTnDOT oriT used subcloned regions in trans to another element, CTnERL, which is also considered to be virtually identical to CTnDOT with the exception that CTnERL lacks the 13-kb ermF region (17,21). Collectively, these observations prompted us to re-evaluate the location of the oriT regions on CTnDOT.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Tetracycline-Related Transcriptional Regulation of the CTnDOT Mobilization Region

2013

Self Cite

View full text Add to dashboard Cite

CTnDOT is a 65-kb conjugative transposon (CTn) in Bacteroides spp. that confers resistance to the antibiotics erythromycin and tetracycline (Tc). Conjugative transfer of CTnDOT is regulated upon exposure of cells to Tc. In the absence of Tc, no transfer is detectable; however, a cascade of regulatory events results in the conjugative transfer of CTnDOT upon Tc induction. Previous studies addressing regulation of CTnDOT conjugative transfer focused primarily on the 13-kb transfer (tra) operon, which encodes the proteins required for assembly of the mating apparatus. We report here that the mob operon that encodes the relaxase and coupling proteins required for mobilization of CTnDOT are regulated at the transcriptional level upon Tc induction. The Xis2d and Exc excision proteins are required for the upregulation of mob transcription upon Tc induction, and yet a deletion of xis2c has no effect. We also show preliminary evidence suggesting that the integrase, IntDOT, may play a regulatory role, as pLYL72 transfer is not detectable when intDOT is provided in trans.

show abstract

Section: Resultsmentioning

confidence: 99%

“…4B). Despite the difference in mob transcription results, the two elements are reported to transfer at similar rates, suggesting that the level of mob expression does not directly affect the frequency of conjugative transfer (21,22).…”

Section: Figmentioning

confidence: 99%

Tetracycline-Related Transcriptional Regulation of the CTnDOT Mobilization Region

2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…The two smallest regions sufficient for mobilization overlapped by 267 bp, and this region was termed the putative oriT. However, when the 267-bp region was cloned onto a plasmid, it was not mobilizable (19,48). We did not specifically test this site in CTn341, but it is possible that there is more than one oriT on these large elements.…”

Section: Discussionmentioning

confidence: 99%

Genetic and Functional Analyses of the mob Operon on Conjugative Transposon CTn 341 from Bacteroides spp

2010

View full text Add to dashboard Cite

Bacteroides are Gram-negative anaerobes indigenous to the intestinal tract of humans, and they are important opportunistic pathogens. Mobile genetic elements, such as conjugative transposons (CTns), have contributed to an increase in antibiotic resistance in these organisms. CTns are self-transmissible elements that belong to the superfamily of integrative and conjugative elements (ICEs). CTn341 is 52 kb; it encodes tetracycline resistance and its transfer is induced by tetracycline. The mobilization region of CTn341 was shown to be comprised of a three-gene operon, mobABC, and the transfer origin, oriT. The three genes code for a nicking accessory protein, a relaxase, and a VirD4-like coupling protein, respectively. The Mob proteins were predicted to mediate the formation of the relaxosome complex, nick DNA at the oriT, and shuttle the DNA/protein complex to the mating-pore apparatus. The results of mutational studies indicated that the three genes are required for maximal transfer of CTn341. Mob gene transcription was induced by tetracycline, and this regulation was mediated through the two-component regulatory system, RteAB. The oriT region of CTn341 was located within 100 bp of mobA, and a putative Bacteroides consensus nicking site was observed within this region. Mutation of the putative nick site resulted in a loss of transfer. This study demonstrated a role of the mobilization region for transfer of Bacteroides CTns and that tetracycline induction occurs for the mob gene operon, as for the tra gene operon(s), as shown previously.

show abstract

“…Previous studies of CTns in members of the genera Bacteroides and Vibrio have indicated that the integrase (int), DNA excision protein (exc) and recA genes are involved in CTn excision (Sutanto et al, 2004;Waldor et al, 1996;Whittle et al, 2002bWhittle et al, , 2006. The Bacteroides CTns CTn341 and CTnDOT require exc for their excision (Bacic et al, 2005;Sutanto et al, 2002).…”

Section: Int-dependent Excision Of Ctnpg1mentioning

confidence: 99%

Characterization of the Porphyromonas gingivalis conjugative transposon CTnPg1: determination of the integration site and the genes essential for conjugal transfer

et al. 2011

View full text Add to dashboard Cite

In our previous study, extensive genomic rearrangements were found in two strains of the Gram-negative anaerobic bacterium Porphyromonas (Por.) gingivalis, and most of these rearrangements were associated with mobile genetic elements such as insertion sequences and conjugative transposons (CTns). CTnPg1, identified in Por. gingivalis strain ATCC 33277, was the first complete CTn reported for the genus Porphyromonas. In the present study, we found that CTnPg1 can be transferred from strain ATCC 33277 to another Por. gingivalis strain, W83, at a frequency of 10−7 to 10−6. The excision of CTnPg1 from the chromosome in a donor cell depends on an integrase (Int; PGN_0094) encoded in CTnPg1, whereas CTnPg1 excision is independent of PGN_0084 (a DNA topoisomerase I homologue; Exc) encoded within CTnPg1 and recA (PGN_1057) on the donor chromosome. Intriguingly, however, the transfer of CTnPg1 between Por. gingivalis strains requires RecA function in the recipient. Sequencing analysis of CTnPg1-integrated sites on the chromosomes of transconjugants revealed that the consensus attachment (att) sequence is a 13 bp sequence, TTTTCNNNNAAAA. We further report that CTnPg1 is able to transfer to two other bacterial species, Bacteroides thetaiotaomicron and Prevotella oralis. In addition, CTnPg1-like CTns are located in the genomes of other oral anaerobic bacteria, Porphyromonas endodontalis, Prevotella buccae and Prevotella intermedia, with the same consensus att sequence. These results suggest that CTns in the CTnPg1 family are widely distributed among oral anaerobic Gram-negative bacteria found in humans and play important roles in horizontal gene transfer among these bacteria.

show abstract

A Bacteroides Conjugative Transposon, CTnERL, Can Transfer a Portion of Itself by Conjugation without Excising from the Chromosome

Cited by 21 publications

References 26 publications

Tetracycline-Related Transcriptional Regulation of the CTnDOT Mobilization Region

Tetracycline-Related Transcriptional Regulation of the CTnDOT Mobilization Region

Genetic and Functional Analyses of the mob Operon on Conjugative Transposon CTn 341 from Bacteroides spp

Characterization of the Porphyromonas gingivalis conjugative transposon CTnPg1: determination of the integration site and the genes essential for conjugal transfer

Contact Info

Product

Resources

About