FIG. 4.

M. tuberculosis enhanceosome formation is dependent upon helical phasing. J774 macrophages were transfected with the wild-type −200 TNF-α luciferase reporter gene or constructs with an insertion of 5 or 10 nt as indicated. These insertions add one-half of a helical turn (5 nt) and a full helical turn (10 nt) and disrupt or restore the precise helical phasing of DNA-bound transcription factors. The cells were then stimulated with M. tuberculosis H37Rv whole sonicate and the increase in inducibility (n-fold) was calculated. All transfections included a control Renilla luciferase plasmid and were normalized to Renilla luciferase activity. Data are presented as means ± standard errors of the means of four independent experiments.