Helicobacter pylori DprA alleviates restriction barrier for incoming DNA

Helicobacter pylori is a Gram-negative bacterium that colonizes human stomach and causes gastric inflammation. The species is naturally competent and displays remarkable diversity. The presence of a large number of restriction-modification (R-M) systems in this bacterium creates a barrier against na...

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Bibliographic Details
Published in:Nucleic acids research 2013-03, Vol.41 (5), p.3274-3288
Main Authors: Dwivedi, Gajendradhar R, Sharma, Eshita, Rao, Desirazu N
Format: Article
Language:English
Subjects:
Bacterial Proteins - chemistry
Bacterial Proteins - physiology
Deoxyribonucleases, Type II Site-Specific - chemistry
DNA Footprinting
DNA Transformation Competence
DNA, Single-Stranded - chemistry
Electrophoretic Mobility Shift Assay
Helicobacter pylori - genetics
Membrane Proteins - chemistry
Membrane Proteins - physiology
Methyltransferases - chemistry
Molecular Biology
Oligodeoxyribonucleotides - chemistry
Protein Binding
Transformation, Bacterial
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Summary:Helicobacter pylori is a Gram-negative bacterium that colonizes human stomach and causes gastric inflammation. The species is naturally competent and displays remarkable diversity. The presence of a large number of restriction-modification (R-M) systems in this bacterium creates a barrier against natural transformation by foreign DNA. Yet, mechanisms that protect incoming double-stranded DNA (dsDNA) from restriction enzymes are not well understood. A DNA-binding protein, DNA Processing Protein A (DprA) has been shown to facilitate natural transformation of several Gram-positive and Gram-negative bacteria by protecting incoming single-stranded DNA (ssDNA) and promoting RecA loading on it. However, in this study, we report that H. pylori DprA (HpDprA) binds not only ssDNA but also dsDNA thereby conferring protection to both from various exonucleases and Type II restriction enzymes. Here, we observed a stimulatory role of HpDprA in DNA methylation through physical interaction with methyltransferases. Thus, HpDprA displayed dual functional interaction with H. pylori R-M systems by not only inhibiting the restriction enzymes but also stimulating methyltransferases. These results indicate that HpDprA could be one of the factors that modulate the R-M barrier during inter-strain natural transformation in H. pylori.
ISSN:0305-1048
1362-4962
DOI:10.1093/nar/gkt024