THE UNSTABLE TETRACYCLINE RESISTANCE GENE OF STREPTOMYCES-LIVIDANS 1326 ENCODES A PUTATIVE PROTEIN WITH SIMILARITIES TO TRANSLATIONAL ELONGATION-FACTORS AND TET(M) AND TET(O) PROTEINS

Streptomyces lividans contains a genetically unstable tetracycline resistance determinant. Nucleotide sequencing revealed an open reading frame of 1,917 nucleotides. The transcriptional start site was mapped at about 110 bp upstream of the ATG codon. The proposed promoter contains an 8-bp perfect inverted repeat between the -10 and -35 regions. The deduced amino acid sequence showed several motifs which are commonly found in many GTP-binding proteins. On the basis of its amino acid sequence, the presumptive S. lividans 1326 protein belongs to the Tet(M)-Tet(O) group of tetracycline resistance proteins and shows significant similarity to translational elongation factors of prokaryotes and eukaryotes.