Heat-inducible translational coupling in Bacillus subtilis.

Bacillus subtilis plasmid pGR71 is a promoter-probe shuttle vector derived from pUB110. The expression of the cat gene on pGR71 in B. subtilis requires the insertion of a Bacillus promoter and a ribosomal binding site (RBS) into the HindIII cloning site immediately upstream from the cat gene. A recombinant plasmid of pGR71, named pGR71-369, was obtained by a spontaneous deletion of a fragment containing most of the inserted HindIII fragment and the replication origin necessary for multiplication in Escherichia coli. The expression of the cat gene in B. subtilis cells carrying this plasmid was inducible by heat. Nucleotide sequence analysis of the upstream region of the cat gene, deletion analysis, and dot blot hybridization analysis of mRNA in various conditions revealed that the cat gene was expressed by heat-inducible translational coupling and that the regulatory region of heat inducibility was present in the upstream region of the cat gene.