Analysis of teichoic acid biosynthesis regulation reveals that the extracytoplasmic function sigma factor sigmaM is induced by phosphate depletion in Bacillus subtilis W23.

The expression of the Bacillus subtilis W23 tar genes specifying the biosynthesis of the major wall teichoic acid, the poly(ribitol phosphate), was studied under phosphate limitation using lacZ reporter fusions. Three different regulation patterns can be deduced from these beta-galactosidase activity data: (i) tarD and tarL gene expression is downregulated under phosphate starvation; (ii) tarA and, to a minor extent, tarB expression after an initial decrease unexpectedly increases; and (iii) tarO is not influenced by phosphate concentration. To dissect the tarA regulatory pattern, its two promoters were analysed under phosphate limitation: The P(tarA)-ext promoter is repressed under phosphate starvation by the PhoPR two-component system, whereas, under the same conditions, the P(tarA)-int promoter is upregulated by the action of an extracytoplasmic function (ECF) sigma factor, sigma(M).

In Bacillus subtilis W23, the duet sigmaXsigmaM, two sigma factors of the extracytoplasmic function subfamily, are required for septum and wall synthesis under batch culture conditions.

The synthesis of poly(RboP), the main Bacillus subtilis W23 teichoic acid, is encoded by tarDF-tarABIJKL operons, the latter being controlled by two promoters designated PtarA-int and PtarA-ext. Analysis by lacZ fusions reveals that PtarA-int activity exhibits sharp increases at the beginning and end of the transition between exponential and stationary growth phase. As confirmed by mRNA quantification, these increases are mediated by ECF sigma factors sigmaX and sigmaM respectively.

Comparison of ribitol and glycerol teichoic acid genes in Bacillus subtilis W23 and 168: identical function, similar divergent organization, but different regulation.

The tar genes directing the synthesis of poly(ribitol phosphate), the main teichoic acid in Bacillus subtilis strain W23, were sequenced. They are organized in two divergently transcribed operons, tarABIJKL and tarDF, as are the tag genes specifying poly(glycerol phosphate) synthesis in B. subtilis 168.

Nucleotide sequence of the Bacillus subtilis temperate bacteriophage SPbetac2.

The Bacillus subtilis 168 chromosomal region extending from 184 degrees to 195 degrees, corresponding to prophage SPbeta, has been completely sequenced using DNA of the thermoinducible SPbetac2 mutant. This 134416 bp segment comprises 187 putative ORFs which, according to their orientation, were grouped into three clusters. Compared to its host, SPbetac2 is characterized by a lower G+C content, shorter mean ORF length, as well as a different usage of start codons.

A 35.7 kb DNA fragment from the Bacillus subtilis chromosome containing a putative 12.3 kb operon involved in hexuronate catabolism and a perfectly symmetrical hypothetical catabolite-responsive element.

The Bacillus subtilis strain 168 chromosomal region extending from 109 degrees to 112 degrees has been sequenced. Among the 35 ORFs identified, cotT and rapA were the only genes that had been previously mapped and sequenced. Out of ten ORFs belonging to a single putative transcription unit, seven are probably involved in hexuronate catabolism.