Multiple Pathways of Plasmid DNA Transfer in Helicobacter pylori

Rohrer, Stefanie; Holsten, Lea; Weiss, Evelyn; Benghezal, Mohammed; Fischer, Wolfgang; Haas, Rainer

doi:10.1371/journal.pone.0045623

Cited by 27 publications

(43 citation statements)

References 38 publications

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“…A possible complementation effect with one of the two chromosomally encoded H. pylori relaxases [75], however, has been excluded by the authors [63]. Interestingly, the two mobilizable plasmids pHel4 and pHel12 do not encode T4SS components ( Table 2), implying that one of the various chromosomal T4SSs could be used for plasmid transfer.…”

Section: Evidence For Multiple Pathways Of Plasmid Transfer In H Pylorimentioning

confidence: 96%

“…Despite several complete H. pylori genome sequences that are available in public databases, the structure and function of plasmids in these bacteria have not been comprehensively characterized yet. About 50 % of clinical H. pylori strains carry cryptic plasmids ranging in size from 2 to 100 kb [62,63]; however, their genetic content, gene organization, and function are still not fully understood. The majority of these plasmids have a size of 2 to 6 kb ( Table 2).…”

Section: Plasmids In H Pylorimentioning

confidence: 99%

“…The majority of these plasmids have a size of 2 to 6 kb ( Table 2). They code for an origin of replication (ori), replication genes (repA or repB), and occasionally, a small ORF with unknown function [62,63]. In contrast, the larger H. pylori plasmids carry a number of additional ORFs with unknown function ( Table 2).…”

Section: Plasmids In H Pylorimentioning

confidence: 99%

“…The fact that H. pylori can carry plasmids with putative mob regions suggests that there is a conjugative mechanism by which these plasmids can be mobilized. Recently, multiple pathways for plasmid DNA transfer in H. pylori have been investigated [63]. The authors proposed that plasmid transfer can proceed by two mechanisms, DNaseIsensitive natural transformation and a DNaseI-resistant alternative (ADR) transfer.…”

Section: Evidence For Multiple Pathways Of Plasmid Transfer In H Pylorimentioning

confidence: 99%

“…However, when the comB gene system is deleted in the recipient strain, plasmid transfer values were reduced in experiments with or without externally given DNaseI, indicating that ComB T4SS is implicated in the uptake of pHel4 and pHel12 plasmids in the recipient by transformation as well as DNaseI-resistant mobilization [63]. Taken together, Rohrer and co-workers provided evidence that H. pylori plasmids pHel4 and pHel12 can be transferred both by conjugation and natural transformation mechanisms [63]. In both cases, the MobA relaxase in the donor and the ComB system in the recipient were strictly necessary.…”

Section: Evidence For Multiple Pathways Of Plasmid Transfer In H Pylorimentioning

confidence: 99%

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DNA transfer in the gastric pathogen Helicobacter pylori

Fernández-González

Backert

2014

J Gastroenterol

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The gastric pathogen Helicobacter pylori is one of the most genetically diverse bacteria. Recombination and DNA transfer contribute to its genetic variability and enhance host adaptation. Among the strategies described to increase genetic diversity in bacteria, DNA transfer by conjugation is one of the best characterized. Using this mechanism, a fragment of DNA from a donor cell can be transferred to a recipient, always mediated by a conjugative nucleoprotein complex, which is evolutionarily related to type IV secretion systems (T4SSs). Interestingly, the H. pylori chromosomes can encode up to four T4SSs, including the cagPAI, comB, tfs3, and tfs4 genes, some of which are known to promote chronic H. pylori infection. The T4SS encoded by the cagPAI mediates the injection of the effector protein CagA and proinflammatory signaling, and the comB system is involved in DNA uptake from the environment. However, the role of tfs3 and tfs4 is not yet clear. The presence of a functional XerD tyrosine recombinase and 5 0 AAAGAATG-3 0 border sequences as well as two putative conjugative relaxases (Rlx1 and Rlx2), a coupling protein (TraG), and a chromosomal region carrying a putative origin of transfer (oriT) suggest the existence of a DNA transfer apparatus in tfs4. Moreover, a conjugation-like DNA transfer mechanism in H. pylori has already been described in vitro, but whether this occurs in vivo is still unknown. Some extrachromosomal plasmids and phages are also present in various H. pylori strains. Genetic exchange among plasmids and chromosomes, and involved DNA mobilization events, could explain part of H. pylori's genetic diversity. Here, we review our knowledge about the possible DNA transfer mechanisms in H. pylori and its implications in bacterial adaptation to the host environment.

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Section: Evidence For Multiple Pathways Of Plasmid Transfer In H Pylorimentioning

confidence: 96%

Section: Plasmids In H Pylorimentioning

confidence: 99%

Section: Plasmids In H Pylorimentioning

confidence: 99%

Section: Evidence For Multiple Pathways Of Plasmid Transfer In H Pylorimentioning

confidence: 99%

Section: Evidence For Multiple Pathways Of Plasmid Transfer In H Pylorimentioning

confidence: 99%

See 3 more Smart Citations

DNA transfer in the gastric pathogen Helicobacter pylori

Fernández-González

Backert

2014

J Gastroenterol

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Recent Advances in Helicobacter pylori Replication: Possible Implications in Adaptation to a Pathogenic Lifestyle and Perspectives for Drug Design

Zawilak-Pawlik

Zakrzewska‐Czerwińska

2017

Current Topics in Microbiology and Immunology

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DNA replication is an important step in the life cycle of every cell that ensures the continuous flow of genetic information from one generation to the next. In all organisms, chromosome replication must be coordinated with overall cell growth. Helicobacter pylori growth strongly depends on its interaction with the host, particularly with the gastric epithelium. Moreover, H. pylori actively searches for an optimal microniche within a stomach, and it has been shown that not every microniche equally supports growth of this bacterium. We postulate that besides nutrients, H. pylori senses different, unknown signals, which presumably also affect chromosome replication to maintain H. pylori propagation at optimal ratio allowing H. pylori to establish a chronic, lifelong infection. Thus, H. pylori chromosome replication and particularly the regulation of this process might be considered important for bacterial pathogenesis. Here, we summarize our current knowledge of chromosome and plasmid replication in H. pylori and discuss the mechanisms responsible for regulating this key cellular process. The results of extensive studies conducted thus far allow us to propose common and unique traits in H. pylori chromosome replication. Interestingly, the repertoire of proteins involved in replication in H. pylori is significantly different to that in E. coli, strongly suggesting that novel factors are engaged in H. pylori chromosome replication and could represent attractive drug targets.

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Type IV Secretion in Gram-Negative and Gram-Positive Bacteria

2017

Current Topics in Microbiology and Immunology

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Type IV secretion systems (T4SSs) are versatile multiprotein nanomachines spanning the entire bacterial cell envelope in Gram-negative and Gram-positive bacteria. They play important roles through the contactdependent secretion of effector molecules into eukaryotic hosts and conjugative transfer of mobile DNA elements as well as contact-independent exchange of DNA with the extracellular milieu. In the last few years, many details on the molecular mechanisms of T4SSs have been elucidated. Exciting structures of T4SS complexes from Escherichia coli plasmids R388 and pKM101, Helicobacter pylori and Legionella pneumophila have been solved. The structure of the F-pilus was also reported and surprisingly revealed a filament composed of pilin subunits in 1:1 stoichiometry with phospholipid molecules. Many new T4SSs have been identified and characterized, underscoring the structural and functional diversity of this secretion superfamily. Complex regulatory circuits also have been shown to control T4SS machine production in response to host cell physiological status or a quorum of bacterial recipient cells in the vicinity. Here, we summarize recent advances in our knowledge of 'paradigmatic' and emerging systems, and further explore how new basic insights are aiding in the design of strategies aimed at suppressing T4SS functions in bacterial infections and spread of antimicrobial resistances.

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Multiple Pathways of Plasmid DNA Transfer in Helicobacter pylori

Cited by 27 publications

References 38 publications

DNA transfer in the gastric pathogen Helicobacter pylori

DNA transfer in the gastric pathogen Helicobacter pylori

Recent Advances in Helicobacter pylori Replication: Possible Implications in Adaptation to a Pathogenic Lifestyle and Perspectives for Drug Design

Type IV Secretion in Gram-Negative and Gram-Positive Bacteria

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