Helicobacter pylori interstrain restriction-modification diversity prevents genome subversion by chromosomal DNA from competing strains

Aras, R. A., Small, A. J., Ando, T., Blaser, M. J. (December 2002) Helicobacter pylori interstrain restriction-modification diversity prevents genome subversion by chromosomal DNA from competing strains. Nucleic Acids Research, 30 (24). pp. 5391-5397. ISSN 0305-1048

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URL: http://www.ncbi.nlm.nih.gov/pubmed/12490707
DOI: 10.1093/nar/gkf686

Abstract

Helicobacter pylori, bacteria that colonize the human gastric mucosa, possess a large number of genes for restriction‐modification (R‐M) systems, and essentially, every strain possesses a unique complement of functional and partial R‐M systems. Nearly half of the H.pylori strains studied possess an active type IIs R‐M system, HpyII, with the recognition sequence GAAGA. Recombination between direct repeats that flank the R‐M cassette allows for its deletion whereas strains lacking hpyIIRM can acquire this cassette through natural transformation. We asked whether strains lacking HpyII R‐M activity can acquire an active hpyIIRM cassette [containing a 1.4 kb kanamycin resistance (aphA) marker], whether such acquisition is DNase sensitive or resistant and whether restriction barriers limit acquisition of chromosomal DNA. Our results indicate that natural transformation and conjugation‐like mechanisms may contribute to the transfer of large (4.8 kb) insertions of chromosomal DNA between H.pylori strains, that inactive or partial R‐M systems can be reactivated upon recombination with a functional allele, consistent with their being contingency genes, and that H.pylori R‐M diversity limits acquisition of chromosomal DNA fragments of ≥1 kb.

Item Type: Paper
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification
bioinformatics > genomics and proteomics > genetics & nucleic acid processing
organism description > bacteria
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > chromosome
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > chromosomes, structure and function > chromosome
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > genomes
CSHL Authors:
Communities: CSHL labs
Depositing User: Matt Covey
Date: December 2002
Date Deposited: 09 Jan 2014 14:48
Last Modified: 09 Jan 2014 14:48
PMCID: PMC140068
Related URLs:
URI: https://repository.cshl.edu/id/eprint/28662

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