Direct regulons of the master virulence regulator AtxA of Bacillus anthracis

AtxA, the master virulence regulator of Bacillus anthracis, regulates the expression of three toxins that are required for the pathogenicity of Bacillus anthracis. Recent transcriptome analyses also showed that AtxA affects a large number of genes on both chromosome and plasmid, suggesting its role as a global regulator. Its mechanism of gene regulation nor binding target in vivo was, however, not well understood. In this work, we conducted ChIP-seq for cataloging binding sites of AtxA in vivo and Cappable-seq for catalogging the transcription start sites on the B. anthracis genome. For detected regulons, single knockout strains were constructed and RNA-seq was conducted for each strain. ChIP-seq was conducted for genomic DNA of B. anthracis 34F2 WT and the strain that produce AtxA with 1xFLAG tag at its C-terminus. Cappable-seq was conducted for B. anthracis 34F2 WT and ΔatxA. RNA-seq was conducted for B. anthracis 34F2 WT, ΔatxA, ΔxrrA, ΔxrrB, and ΔxrrC. All strains were grown in NBY medium supplemented with 8% NaHCO3 under 15% CO2 at 37°C.