Whole sequence of spoIIIE-like, sporulation-inhibitory, and transfer gene (spi) in a conjugative plasmid, pSA1.1, of Streptomyces azureus and detection of spi-like gene in the actinomycete chromosome.

The nucleotide sequence of spoIIIE-like and the sporulation-inhibitory and transfer gene (spi) in a conjugative plasmid, pSA1.1, of Streptomyces azureus were examined to detect the promoter region. Using Southern blotting and a spi fragment as probe, spi-like genes were detected in chromosomes of the host and other actinomycetes. These results suggest that there is a spi- and spoIIIE-like gene in chromosomes of some actinomycetes.