subtilis, by the phosphoenolpyruvate: sugar phosphotransferase

system (PTS) [6]. The PTS is a protein system composed of general and sugar-specific components. The enzyme I (EI) and the phosphohistidine carrier protein (HPr), relay a phosphoryl group from phosphoenolpyruvate (PEP) to the sugar-specific proteins IIA and IIB. The last component of this system, IIC (in some cases also IID), is an integral membrane protein permease that recognizes and transports the sugar molecules, which are phosphorylated by component IIB. There CX-6258 in vivo are several PTS component II encoded in the genome of B. subtilis, each one having a specific sugar as substrate [7]. B. subtilis displays a pattern of preferential SYN-117 mouse carbon source consumption,

depending on their varying metabolic rates, which in turn result in differing growth rates. Glucose is considered the preferred carbon source as it sustains the highest growth rate and the same applies in the case of E. coli [7]. Repression of the genes involved in the metabolism of sugars is Selleckchem mTOR inhibitor part of a global phenomenon known as carbon catabolite repression (CCR). In B. subtilis, this phenomenon occurs due to PTS-mediated phosphorylation of regulatory proteins and GlcT controlling antitermination. In most cases, CCR is defined by the presence of catabolic responsive elements sites (CRE) in the 5′ regions of the regulated genes. The CRE DNA sequences are recognized by the catabolite control protein A (CcpA), whose repressed gene encoding functions relate to the utilization of alternative carbon sources and other stress conditions, in the presence of

a preferential carbon source, such as glucose [8, 9]. A global view of the cellular transcriptional response can now be accomplished using microarray technology. This type of of study provides an instantaneous snapshot of the way cells function, under specific conditions. The data generated using this technology is useful for revealing the nature of the complex regulatory interactions in the cell. At the present time several reports exist, describing the use of microarrays to study B. subtilis under diverse conditions; for example in the presence ADP ribosylation factor of acid [10], in response to thermic shock [11], anaerobiosis [12] and in the presence or absence of glucose [8], among others. These results provide data that will enable the construction of a detailed regulatory network and help to elucidate how regulatory proteins interact with their effectors. In this work, we analysed the regulatory network of B. subtilis, when grown in a complex medium in the absence or presence of glucose. This study enabled the identification of network modules, coordinating the response of genes with related functions. The results obtained were compared to those from our previous study where E. coli was employed[13].