The appropriate location and orientation of the kanamycin resistance gene (kmr) cloned on multicopy plasmids were determined by subcloning experiments. The transcription start site was identified by high-resolution SI mapping and the kmr mRNA was shown to have a long leader of about 400 bp. An additional transcript upstream of the kmr gene was also detected, which ran in the opposite direction and overlapped 2 to 3 nucleotides with the kmr transcript. The presumptive promoter region of this physiologically unidentified RNA was similar to the Escherichia coli promoter consensus sequence both in the -10 and -35 regions, whereas the putative promoter region of the kmr gene exhibited sequence similarities in the -10 region to the promoters of the endoglycosidase H (endoH) and the viomycin phosphotransferase (vph) genes from Streptomyces.
ASJC Scopus subject areas
- Drug Discovery