International Journal of
Genetics and Molecular Biology

  • Abbreviation: Int. J. Genet. Mol. Biol.
  • Language: English
  • ISSN: 2006-9863
  • DOI: 10.5897/IJGMB
  • Start Year: 2009
  • Published Articles: 131

Full Length Research Paper

Plasmid-mediated transformation of Escherichia coli having a dependence on the heat-shock protein GroEL

Pulakesh Aich2, Arijit Kumar Chatterjee1, Monobesh Patra1 and Tarakdas Basu1*
1Department of Biochemistry and Biophysics, University of Kalyani, Kalyani – 741 235, West Bengal, India. 2Department of Microbiology, University of Kalyani, Kalyani – 741 235, West Bengal, India.
Email: [email protected]

  •  Accepted: 27 April 2011
  •  Published: 28 April 2011


When the cells of Escherichia coli mutant in heat-shock regulator protein sigma-32 were transformed with plasmid pUC19 DNA, the transformation efficiency (TRE) of the mutant strain was about 10% of the wild type (wt) strain, indicating the role of heat-shock protein(s) in the transformation process. In order to search for the protein(s), when three different E. coli mutants in three important heat-shock proteins (DnaK, DnaJ and GroEL) were studied, TRE of dnaK and dnaJ mutants was similar to that of their wt strain; but TRE of groEL mutant was drastically less, that is, it is almost 10% of the TRE of its wt counterpart. On transformation of the groEL mutant with a groEL-bearing plasmid, the transformed cells elicited higher TRE like wt cells. Over-expression of GroEL by the brief heat-shock step of the transformation procedure was also evident from immuno-precipitation, as well as western blot studies. All these results suggested that GroEL had a positive role in the transformation phenomenon.


Key words: Escherichia colitransformation, pUC19 DNA, sigma-32, GroEL