Conserved transcriptional regulatory networks in Lactobacillales order species

Currently, there exist more than 1000 sequenced bacterial genomes, however, little is known about the global transcriptional regulation properties of their genes and the phylogenetic conservation of the elements involved. In this context, we generated a set of 94 matrices for bacterial transcriptional factor binding sites (BS) collecting data from different public data bases (RegulonDB, TractorDB, BSdatabase) and literature. Using the algorithms Consensus-Patser and Motif Sampler-Scanner we searched the BS on the upstream genes (-300/+50 bp) of 9 species of Lactobacillales order. As a result, we generated 9 global transcriptional regulatory networks, each one containing on average 80 regulons and 4 BS per gene, covering more than the 75% of the total of genes. The topological analysis indicated that all the networks present a Scale Free distribution, with the presence of feed-forward loops, auto and chain regulations and single/multiple input interactions. The next step was to determine the grade of homology between these networks. For this, first we identified the homologous genes in all the species, then, we selected those of them that contained the same BS. In general, homolog genes share at least one BS on its regulatory region, highlighting the regulons LysR (stress control), ArgR (arginine repressor) and CRP (cAMP receptor) as the most conserved families in all the genomes analyzed. This work provides for the first time, information about the structure and conservation of transcriptional regulatory networks within a bacterial order. Financing: Fondecyt 1110427; FONDAP 15090007 and MECESUP UCH0713.