Increased expression of the gentamicin resistance gene by a Tn3 sequence located at the upstream region

Abstract

Recombinant plasmids designated as pCH1 and pCH21 were constructed to determine the influence of the bla sequence on the expression of the gentamicin resistance gene which is located downstream of Tn3. Minimal inhibitory concentration (MIC) test and Northern hybridization results with the constructed plasmids showed that the transcription of the gentamicin resistance gene was initiated from the promoter, located downstream from the Pst\ site within the bla gene, and the hybrid promoter created by IR sequences of Tn3. Although the read-through transcription from the bla promoter did not occur, the transcription of the bla gene increased the expression of the gentamicin resistance gene.