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Molecular mechanisms of HipA-mediated multidrug tolerance and its neutralization by HipB

Maria A Schumacher1, Kevin M Piro, Weijun Xu

  • 1Department of Biochemistry and Molecular Biology, University of Texas, M. D. Anderson Cancer Center, Unit 1000, Houston, TX 77030, USA. maschuma@mdanderson.org

Science (New York, N.Y.)
|January 20, 2009
PubMed

Insights

Bacterial multidrug tolerance, driven by persister cells, is a major antibiotic challenge. Researchers elucidated the structure and function of HipA, a key persistence factor, and its inhibitor HipB, revealing mechanisms of antibiotic resistance.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Structural Biology

Background:

  • Bacterial multidrug tolerance hinders antibiotic efficacy.
  • Persister cells, a dormant subpopulation, are responsible for this tolerance.
  • The HipA protein in Escherichia coli is a critical factor in bacterial persistence.

Purpose of the Study:

  • To elucidate the structural basis of HipA's kinase activity.
  • To understand the mechanism by which HipB neutralizes HipA.
  • To reveal the molecular interactions governing HipA-mediated persistence and HipB regulation.

Main Methods:

  • X-ray crystallography was used to determine the structures of HipA and a HipA-HipB-DNA complex.
  • Biochemical assays were performed to assess HipA's kinase activity and HipB's inhibitory function.

Main Results:

  • HipA exhibits a eukaryotic serine/threonine kinase-like fold and phosphorylates the translation factor EF-Tu, suggesting a role in cell stasis.
  • The HipA-HipB-DNA complex structure revealed HipB's DNA-binding mechanism, significant DNA bending, and novel HipA-DNA interactions.
  • Dimeric HipB inhibits HipA's kinase activity through sequestration and conformational inactivation.

Conclusions:

  • These findings provide insights into the molecular mechanisms of HipA-mediated bacterial persistence.
  • The study reveals how HipB counteracts HipA activity, offering potential targets for antibiotic development.
  • Understanding these interactions is crucial for overcoming antibiotic resistance.

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