Bacillus subtilis requires a "stringent" Shine-Dalgarno region for gene expression.

A series of plasmids was constructed differing only in the sequence of the Shine-Dalgarno region preceding the leukocyte interferon-A gene. This series of plasmids was used to test the efficiency of interferon expression in both Bacillus subtilis and Escherichia coli. In B. subtilis, interferon expression was much more sensitive to changes in the sequence of the Shine-Dalgarno region than in E. coli and it appeared to require more homology to the 3' end of 16S ribosomal RNA.