Analysis of the promoter region of the cloned kanamycin resistance gene (kmr) from streptomyces kanamyceticus

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.