Characterization of novel transcription factors by the one-hybrid system in combination with SPR assays. (A) Detection of novel transcription factors by the bacterial one-hybrid system. The promoters of Rv2031 and Rv3874/3875 were cloned in pBXcmT and were used to screen the M. tuberculosis subgenomic library according to the description in Materials and Methods. The regulators that interact with the promoters were isolated from the library and are listed on the left. The structure of the operon of Rv2031 or the Rv3874/3875 is listed on the right. (B) SPR assays for the interaction between the new transcription factors and the promoter. Several new transcription factors of Rv2021, Rv2034, Rv3416, Rv3678, and Rv3681 were expressed and purified. The SPR assaying procedure followed the previous description. An overlay plot was produced for depicting the interaction between the promoter DNA with the different concentrations of transcription factor (30 nM, 60 nM, and 90 nM). RU, response units; s, seconds.
