The Effect of rpoH for Heat Shock Gene Expression on Plasmid Transformation

Abstract

The heat shock method of transformation is done by rapidly heating cold cells. The rpoH gene encodes an RNA polymerase that is highly expressed under heat shock and transcribes downstream heat shock proteins. Transformation efficiencies of two strains of bacteria were compared with the single difference between the two strains being a temperature sensitive mutation in the rpoH gene in order to assess whether any of the genes induced by the heat shock cascade were important for the transformation process. It was expected that there would be a much higher transformation efficiency in the wild type strain over the mutant strain if the heat shock proteins aided the transformation process. While the mutant strain was unable to grow in high temperatures that the wild type could survive in, the effect of the rpoH gene expression in aiding transformation efficiency was unclear. There was a slightly greater transformation efficiency of the wild type over the mutant strain, but it was not a dramatic difference. Therefore, either the rpoH gene was expressing well enough in the mutant strain or the downstream heat shock proteins do not have a strong effect in aiding transformation.