Characterization of the ColE1 mobilization region and its protein products

Boyd, Alan; Archer, J. A. K.; Sherratt, David J.

doi:10.1007/bf02464922

Cited by 71 publications

(4 citation statements)

References 48 publications

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“…They were assigned to the group of theta plasmids. In pHel4 and pHel12, a putative mob region was identified, showing best homologies to proteins MbeA, MbeB, MbeC and MbeD of colicinogenic plasmids, such as pColE1 [13], [21]. The MbeA protein of the ColE1 plasmid is an atypical relaxase, because it lacks two conserved histidine residues in the third conserved amino acid sequence motif (motif III) [22], present in most relaxases.…”

Section: Introductionmentioning

confidence: 99%

Multiple Pathways of Plasmid DNA Transfer in Helicobacter pylori

et al. 2012

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Many Helicobacter pylori (Hp) strains carry cryptic plasmids of different size and gene content, the function of which is not well understood. A subgroup of these plasmids (e.g. pHel4, pHel12), contain a mobilisation region, but no cognate type IV secretion system (T4SS) for conjugative transfer. Instead, certain H. pylori strains (e.g. strain P12 carrying plasmid pHel12) can harbour up to four T4SSs in their genome (cag-T4SS, comB, tfs3, tfs4). Here, we show that such indigenous plasmids can be efficiently transferred between H. pylori strains, even in the presence of extracellular DNaseI eliminating natural transformation. Knockout of a plasmid-encoded mobA relaxase gene significantly reduced plasmid DNA transfer in the presence of DNaseI, suggesting a DNA conjugation or mobilisation process. To identify the T4SS involved in this conjugative DNA transfer, each individual T4SS was consecutively deleted from the bacterial chromosome. Using a marker-free counterselectable gene deletion procedure (rpsL counterselection method), a P12 mutant strain was finally obtained with no single T4SS (P12ΔT4SS). Mating experiments using these mutants identified the comB T4SS in the recipient strain as the major mediator of plasmid DNA transfer between H. pylori strains, both in a DNaseI-sensitive (natural transformation) as well as a DNaseI-resistant manner (conjugative transfer). However, transfer of a pHel12::cat plasmid from a P12ΔT4SS donor strain into a P12ΔT4SS recipient strain provided evidence for the existence of a third, T4SS-independent mechanism of DNA transfer. This novel type of plasmid DNA transfer, designated as alternate DNaseI-Resistant (ADR) mechanism, is observed at a rather low frequency under in vitro conditions. Taken together, our study describes for the first time the existence of three distinct pathways of plasmid DNA transfer between H. pylori underscoring the importance of horizontal gene transfer for this species.

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Section: Introductionmentioning

confidence: 99%

Multiple Pathways of Plasmid DNA Transfer in Helicobacter pylori

et al. 2012

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“…). Two of these genes, mbeB and mbeD , belong to the ColE1 plasmid mobilization region that encodes genes necessary to promote its specific transfer in the presence of conjugative plasmids . Interestingly, the TW10598 plasmid sequence is a close match with the p52 plasmid of the ETEC strain H10407 , except for two mismatches (99.96% identity) and p52 being 363 base pairs shorter.…”

Section: Resultsmentioning

confidence: 99%

Improving genome annotation of enterotoxigenic Escherichia coli TW10598 by a label‐free quantitative MS/MS approach

2015

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The most commonly used genome annotation processes are to a great extent based on computational methods. However, those can only predict genes that have been described earlier or that have sequence signatures indicative of a gene function. Here, we report a synonymous proteogenomic approach for experimentally improving microbial genome annotation based on label-free quantitative MS/MS. The approach is exemplified by analysis of cell extracts from in vitro cultured enterotoxigenic Escherichia coli (ETEC) strain TW10598, as part of an effort to create a new reference ETEC genome sequence. The proteomic analysis yielded identification of 2060 proteins, out of which 312 proteins were originally described as hypothetical. For 84% of the identified proteins we have provided description of their relative quantitative levels, among others, for 20 abundantly expressed ETEC virulence factors. Proteogenomic mapping supported the existence of four protein-coding genes that had not been annotated, and led to correction of translation start positions of another nine. The addition of the proteomic analysis into TW10598 genome re-annotation project improved quality of the annotation, and provided experimental evidence for a significant portion of ETEC expressed proteome. Data are available via ProteomeXchange with identifier PXD002473 (http://proteomecentral.proteomexchange.org/dataset/PXD002473).

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“…The 3315 bp plasmid comprises RNA I Modulator protein, indicating that this plasmid has the ability to control plasmid DNA replication by modulating the initiation of transcription of the primer RNA precursor (Banner et al 1987). Moreover, this plasmid contains mobilization proteins (MobA-D), which are necessary for the horizontal transmission of genetic material via bacterial conjugation (Boyd et al 1989). To produce a single-stranded substrate for MobA to cleave, MobC extends DNA strands that have been split apart by nick sites at the origin of transfer (Zhang and Meyer 1997).…”

Section: Discussionmentioning

confidence: 99%

“…The 3460 bp, 2817 bp, and 3287 bp isolated plasmids may be involved in the horizontal transfer of genetic material during bacterial conjugation. Similarly, it seems that these plasmids help in plasmid DNA replication by regulating the transcription initiation of the primer RNA precursor (Banner et al 1987;Boyd et al 1989). A replication initiation protein is encoded by the smallest plasmid found in S. flexneri, which is 973 bp in size but lacks any specific virulence factors.…”

Section: Discussionmentioning

confidence: 99%

Novel plasmids in multidrug-resistant Shigella flexneri serotypes from Pakistan

et al. 2023

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Shigellosis is the main cause of food and waterborne diarrhea and is an emerging threat to human health. The current study characterized the indigenous multidrug-resistant Shigella flexneri serotypes for their plasmid profiles and genetic diversity, to characterize the plasmid evolutionary patterns and distribution. In total, 199 identified S. flexneri isolates belonging to six different serotypes were analyzed for plasmid profiling, followed by an analysis of whole genome sequencing. All isolates of S. flexneri resistant to antibiotics harbored multiple copies of plasmids with sizes ranging from 1.25 kbp to 9.4 kbp. These isolates were clustered into 22 distinct plasmid patterns, labeled as p1-p22. Among these, p1 (24%) and p10 (13%) were the predominant plasmid profiles. All S. flexneri strains were grouped into 12 clades with a 75% similarity level. Also, a significant association was observed among the plasmid patterns, p23 and p17 with the drug-resistant patterns AMC, SXT, C (19.5%) and OFX, AMC, NA, CIP (13.5%), respectively. Moreover, the most widespread plasmid patterns p4, p10, and p1 showed a significant association with the serotypes 1b (29.16%), 2b (36%), and 7a (100%), respectively. After plasmid sequence assembly and annotation analysis, a variety of small plasmids that vary in size from 973 to 6200 bp were discovered. Many of these plasmids displayed high homology and coverage with plasmids from non-S. flexneri. Several novel plasmids of small size were discovered in multidrug-resistant S. flexneri. The data also showed that plasmid profile analysis is more consistent than antibiotic susceptibility pattern analysis for identifying epidemic strains of S. flexneri isolated in Pakistan.

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Characterization of the ColE1 mobilization region and its protein products

Cited by 71 publications

References 48 publications

Multiple Pathways of Plasmid DNA Transfer in Helicobacter pylori

Multiple Pathways of Plasmid DNA Transfer in Helicobacter pylori

Improving genome annotation of enterotoxigenic Escherichia coli TW10598 by a label‐free quantitative MS/MS approach

Novel plasmids in multidrug-resistant Shigella flexneri serotypes from Pakistan

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