Nucleotide sequence and organization of Bacillus subtilis RNA polymerase major sigma (sigma 43) operon.

The gene coding for Bacillus subtilis RNA polymerase major sigma 43, rpoD, was cloned together with its neighboring genes in a 7 kb EcoRI fragment. The complete nucleotide sequence of a 5 kb fragment including the entire rpoD gene revealed the presence of two other genes preceding rpoD in the order P23-dnaE-rpoD. The dnaE codes for DNA primase while the function of P23 remains unknown. The three genes reside in an operon that is similar in organization to the E. coli RNA polymerase major sigma 70 operon, which is composed of genes encoding small ribosome protein S21 (rpsU), DNA primase (dnaG), and RNA polymerase sigma 70 (rpoD). There is a relatively high degree of base and amino acid homology between the DNA primase and sigma genes. The most significant differences between the two operons are observed in the molecular size of the first genes (P23 and rpsU), the complete lack of amino acid homology between P23 and S21, the molecular weights of the two rpoD genes, the size of the intercistronic region between the first two genes, and the regulatory elements of the operon.     

The Bacillus subtilis ureABC operon.

The Bacillus subtilis ureABC operon encodes homologs of the three subunits of urease enzymes of the family Enterobacteriaceae. Disruption of ureC prevented utilization of urea as a nitrogen source and resulted in a partial growth defect in minimal medium containing limiting amounts of arginine or allantoin as the sole nitrogen source.     

Nucleotide sequence of the Bacillus subtilis ribosomal RNA operon, rrnB

The primary sequence of DNA covering a complete ribosomal RNA (rRNA) operon from Bacillus subtilis, designated rrnB has been elucidated. Following a set of tandem promoters, rrnB encodes: (i) a 16S and a 23S rRNA determinant with no tRNA spacer region in between; (ii) a 5S rRNA determinant; and (iii) 21 contiguous tRNA species; before (iv) two characteristic terminator hairpins are found. More than 7 kb are included within this operon, which maps between aroG and thr5 on the B. subtilis chromosome. This represents the first report of the entire sequence of an rRNA operon from B. subtilis or from any Gram-positive organism.