Effect of host species on recG phenotypes in Helicobacter pylori and Escherichia coli. Academic Article uri icon

Overview

abstract

  • Recombination is a fundamental mechanism for the generation of genetic variation. Helicobacter pylori strains have different frequencies of intragenomic recombination, arising from deletions and duplications between DNA repeat sequences, as well as intergenomic recombination, facilitated by their natural competence. We identified a gene, hp1523, that influences recombination frequencies in this highly diverse bacterium and demonstrate its importance in maintaining genomic integrity by limiting recombination events. HP1523 shows homology to RecG, an ATP-dependent helicase that in Escherichia coli allows repair of damaged replication forks to proceed without recourse to potentially mutagenic recombination. Cross-species studies done show that hp1523 can complement E. coli recG mutants in trans to the same extent as E. coli recG can, indicating that hp1523 has recG function. The E. coli recG gene only partially complements the hp1523 mutation in H. pylori. Unlike other recG homologs, hp1523 is not involved in DNA repair in H. pylori, although it has the ability to repair DNA when expressed in E. coli. Therefore, host context appears critical in defining the function of recG. The fact that in E. coli recG phenotypes are not constant in other species indicates the diverse roles for conserved recombination genes in prokaryotic evolution.

publication date

  • November 1, 2004

Research

keywords

  • DNA Helicases
  • Escherichia coli
  • Escherichia coli Proteins
  • Helicobacter pylori
  • Sequence Homology, Amino Acid

Identity

PubMed Central ID

  • PMC524884

Scopus Document Identifier

  • 7744228869

Digital Object Identifier (DOI)

  • 10.1128/JB.186.22.7704-7713.2004

PubMed ID

  • 15516585

Additional Document Info

volume

  • 186

issue

  • 22