Journal of Proteomics & Bioinformatics
Open Access

Abstract

Bacillus clausii and Bacillus halodurans lack GlnR but Possess Two Paralogs of glnA

Abbas Farazmand, Bagher Yakhchali, Parvin Shariati and Hamideh Ofoghi

Bacillus clausii and Bacillus halodurans lack GlnR but possess a single TnrA regulator of nitrogen assimilation and two paralogs of glnA. Bacillus clausii contains two paralogs of the gene encoding the glutamine synthetase (GS), glnA1 (ABC3940) and glnA2 (ABC2179). The glnA1 gene contains a TnrA site. This TnrA site is located downstream of the -10 region of the promoter. However, the glnA2 gene does not contain the TnrA site at its regulatory region. Bacillus haloduranspossesses two paralogs of glnA, both with TnrA-binding sites. The glnA1 (BH2360) gene contains a TnrA site, which overlaps the -10 region of the glnA1 promoter, and the glnA2 (BH3867) gene contains a TnrA site downstream of the -10 region of its promoter. Also, the Bacillus subtilis dicistronic glnRA operon, which encodes GlnR and GS, contains two TnrA sites (glnRAo1 and glnRAo2) in its promoter region. The glnRAo2 site, which overlaps the -35 region of the glnRA promoter, was shown to be required for regulation by TnrA. These results indicate that TnrA regulates the expression of GS, through binds to TnrA sites which overlaps the -35 and -10 promoter elements or lies downstream of the theirs of the glnA or glnRApromoters.