4A). Figure 4 Characterization of the conserved SAHA solubility dmso sequence motif for MtrA in mycobacteria and C. glutamicum. (A) EMSA assays for see more validating the binding of MtrA with regulatory sequences of

several potential target genes from M. tuberculosis. The promoter DNA of M. tuberculosis dnaA gene was used as positive control. An unrelated DNA was used as negative control. Several DNA substrates, namely, Rv0341_up, Rv0574c_up, and Rv3476c_up, were amplified from their promoter regions using specific primers. Several regulatory sequences of potential target genes from C. glutamicum including CglumepAp and CgluproPp, were amplified and used as DNA substrates. (B) A blast assay for the conserved sequence https://www.selleckchem.com/products/epoxomicin-bu-4061t.html motif recognition by MtrA. Sequence alignment was carried and visualized by local BioEdit software. The complete consensus sequence is indicated by the stars under the base in the upper panel. Sequence logo was generated by WebLogo tool. A further logo assay for the consensus sequence was conducted using the WebLogo tool [16]. A more general conserved motif for MtrA recognition was mapped out (Fig. 4B). In all, 155 potential target genes were characterized from the M. tuberculosis genome (Additional file 4), and

264 genes were characterized from the M. smegmatis genome (Additional file 5). Effects of mtrA gene expression level on mycobacterial drug resistance and cell morphology The mRNA antisense expression of the mtrA gene in M. smegmatis showed a regulatory effect of mtrA on mycobacterial drug resistance and cell morphology [17]. No substantial change was observed for the general growth of the recombinant mycobacterial strains. However, as shown in Fig. 5A, the recombinant mycobacterial cells became sensitive to the anti-TB drugs isoniazid and streptomycin, as evidenced by their inhibited growth in the presence of 25 μg/mL of isoniazid

or 0.5 μg/mL of streptomycin in the medium. In contrast, no noticeable inhibition was observed for two other drugs, ethambutol and rifampicinB (data not shown). With a general growth of the recombinant mycobacterial strains resulting in minimal change, the cell morphology was further Silibinin examined using the scanning electron microscopy (SEM) technique. As shown in Fig. 5B, the cell lengthened when 20 ng/mL tetracycline was added to the medium to induce expression of the antisense mtrA mRNA (right panel). Figure 5 Effects of the expression level of mtrA gene on target genes and cell growth in M. smegmatis. (A) Drug resistance assays. The antimicrobial activity of four first-line anti-tuberculosis drugs against M. smegmatis was determined as described under “”Materials and Methods”". Representative growth curves for isonizid and streptomycin are shown. (B) Scanning electron microscopy assay of cell morphology. The experiment was carried out as described in the “”Materials and Methods”". Representative images are shown.