Fig. 1: Impact of HigB toxins on growth and protein synthesis.
a Schematic representation of the three HigBA-like systems of M. tuberculosis. Toxins are shown in red, antitoxins in blue and the chaperone of the TAC system (SecBTA) in green. The amino acid length of each protein is given as a subscript and the locus tag for each gene within color arrows. b Phylogenetic tree of M. tuberculosis HigB toxins (red) and E. coli RelE (orange). The percentage of sequence identity between pairs of toxins is shown on the right (colored brackets). c Expression of HigB toxins in vivo. M. smegmatis transformed with pGMC-vector (-), HigBTAC, HigBTAC [K95A], HigB2 or HigB3 or TAC (HigB/HigA/SecB)TAC were serial diluted and spotted on LB agar plates supplemented with or without Atc inducer at the indicated concentration. Plates were incubated for 3 days at 37 °C. d In vitro transcription/translation reactions assessing the synthesis of GFP protein in the absence (-) or presence of increasing concentrations of HigB toxins, (0.3, 3, and 6 µM). Samples were separated by SDS-PAGE and revealed by western blot using an anti-GFP antibody. Representative results of three independent experiments are shown.
