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One-step Negative Chromatographic Purification of Helicobacter pylori Neutrophil-activating Protein Overexpressed in Escherichia coli in Batch Mode
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The RecA protein of Helicobacter pylori requires a posttranslational modification for full activity

Wolfgang Fischer1, Rainer Haas

  • 1Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, D-80336 Munich, Germany. fischer@m3401.mpk.med.uni-muenchen.de

Journal of Bacteriology
|January 20, 2004
PubMed

Insights

Helicobacter pylori RecA protein undergoes a posttranslational modification, dependent on glycosylation and lipopolysaccharide biosynthesis genes, which is crucial for its DNA repair function. This modification is vital for the bacterium

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • RecA protein is essential for homologous recombination and the SOS system in bacteria.
  • Homologous recombination generates microdiversity in Helicobacter pylori strains.
  • Previous studies suggested posttranslational modification of H. pylori RecA.

Purpose of the Study:

  • To investigate the genetic basis and functional significance of RecA posttranslational modification in H. pylori.
  • To determine the role of glycosylation and lipopolysaccharide biosynthesis in RecA modification.

Main Methods:

  • Site-directed mutagenesis of a putative glycosylation site on RecA.
  • Analysis of RecA electrophoretic mobility and function in modified strains.
  • Investigating the involvement of downstream genes and glycosylation/LPS pathways.

Main Results:

  • Two genes downstream of recA are involved in RecA modification.
  • The modification process depends on genes for glycosylation and lipopolysaccharide (LPS) biosynthesis.
  • Mutagenesis of a putative glycosylation site yielded unmodified RecA.
  • The modification is not essential for membrane targeting or cell division.
  • The modification is necessary for the full DNA repair function of RecA.

Conclusions:

  • H. pylori RecA protein is posttranslationally modified through a pathway linked to glycosylation and LPS biosynthesis.
  • This modification is essential for optimal RecA function in DNA repair, suggesting an adaptation to H. pylori's environment.
  • The findings provide insights into the regulation and function of RecA in bacterial genome maintenance and evolution.

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