Fig. 6.

Reporter activity of mbtB and bfrA promoter fusions to lacZ in two MAP strains. The line indicates the background reporter activity of the empty vector (pSM128). Both mbtB and bfrA are active in MAP. The activity of MAP mbtB promoters is lower in comparison to that of MTB mbtB. The bfrA promoter from a sheep MAP strain showed consistently lower activity under high-iron conditions, as shown in the SM3 background. Open bars, transcription in iron-depleted medium; closed bars, transcription in iron-rich medium; c, cattle; s, sheep. Means of three independent experiments, each performed in triplicate, are shown.