Nucleotide sequence homology of the tetracycline-resistance determinant naturally maintained in Bacillus subtilis Marburg 168 chromosome and the tetracycline-resistance gene of B. subtilis plasmid pNS1981

Abstract The nucleotide sequence (1579 bp) of tetracycline-resistance determinant and flanking regions of the cloned 5.1 kb DNA fragment from Bacillus subtilis GSY908 chromosome (Sakaguchi, R. and Shishido, K. (1988) Biochim. Biophys. Acta 949, 49–57) were determined and compared with those of the B. subtilis tetracycline-resistance plasmid pNS1981. The tetracycline-resistance structural ( tet ) genes of the B. subtilis GSY908 chromosome ( tet BS908) and pNS1981 ( tet pNS1981) were found to be highly homologous (80% identical). Both tet genes were composed of 1374 bp and 458 amino-acid residues initiating from a GTG codon preceded by a ribosome-binding site (RBS-2). Upstream from tet BS908 there exists a short open reading frame (20 amino acids) initiating from a ATG codon preceded by its own RBS (RBS-1). This leader sequence was also highly homologous to that of tet pNS1981 except for a deletion of one bp between the RBS-1 and the ATG codon.