Open AccessRegulation of the Bacillus subtilis Extracytoplasmic Function Protein σ Y and Its Target Promoters
Author(s) -
Min Cao,
Letal I. Salzberg,
ChiChin Tsai,
Thorsten Mascher,
Carla Y. Bonilla,
Tao Wang,
Rick W. Ye,
Leticia Márquez-Magaña,
John D. Helmann
Publication year - 2003
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.185.16.4883-4890.2003
Subject(s) - operon , biology , bacillus subtilis , gene , promoter , transposable element , transcription (linguistics) , derepression , genetics , mutant , sigma factor , regulation of gene expression , transcription factor , gene expression , psychological repression , bacteria , linguistics , philosophy
The Bacillus subtilis extracytoplasmic function sigma factor sigma(Y) is of unknown function. We demonstrate that the sigY operon is expressed from an autoregulatory promoter site, P(Y). We selected for transposon-induced mutations that upregulate P(Y) transcription in an attempt to identify genes involved in sigma(Y) regulation. The resulting insertions disrupted yxlC, the gene immediately downstream of sigY. However, the phenotype of the yxlC::Tn10 insertion was due to polarity on the downstream genes of the sigY operon; a nonpolar insertion in yxlC did not lead to derepression of P(Y). Further analyses revealed that both yxlD and yxlE encoded proteins important for the negative regulation of sigma(Y) activity. A comparison of the transcriptomes of wild-type and yxlC::Tn10 mutant strains revealed elevated expression of several operons. However, only one additional gene, ybgB, was unambiguously identified as a direct target for sigma(Y). This was supported by analysis of direct targets for sigma(Y) transcription with whole-genome runoff transcription followed by macroarray analysis.