The Rok protein of Bacillus subtilis represses genes for cell surface and extracellular functions.

Journal of bacteriology

PubMedID: 15743949

Albano M, Smits WK, Ho LT, Kraigher B, Mandic-Mulec I, Kuipers OP, Dubnau D. The Rok protein of Bacillus subtilis represses genes for cell surface and extracellular functions. J Bacteriol. 2005;187(6):2010-9.
Rok is a repressor of the transcriptional activator ComK and is therefore an important regulator of competence in Bacillus subtilis (T. T. Hoa, P. Tortosa, M. Albano, and D. Dubnau, Mol. Microbiol. 43:15-26, 2002). To address the wider role of Rok in the physiology of B. subtilis, we have used a combination of transcriptional profiling, gel shift experiments, and the analysis of lacZ fusions. We demonstrate that Rok is a repressor of a family of genes that specify membrane-localized and secreted proteins, including a number of genes that encode products with antibiotic activity. We present evidence for the recent introduction of rok into the B. subtilis-Bacillus licheniformis-Bacilllus amyloliquefaciens group by horizontal transmission.