Figure 2

SigG1 interaction with RsfG (a) Co-transcription of sigG1 and rsfG (lane 1) was observed by RT-PCR using as template DNase I-treated RNA from the wild-type (WT). Genomic DNA (gDNA) was used as PCR positive control. Transcription start sites (TSS) were mapped by 5′RACE PCR and sequencing. (b) BACTH assays for SigG1-RsfG binding in vivo. Positive controls pUT18Czip and pKT25-zip (+ ctrl); Negative control with empty vectors pUT18C and pKT25 (-ctrl); T18-SigG1 and T25-RsfG (1) SigG1-T18 and T25-RsfG (2); T18-RsfG and T25-RsfG (3); pUT18 and T25-RsfG (4); T18-SigG1 and T25-SigG1 (5); pUT18 and T25-SigG1 (6); T25-RsfG and truncated forms of SigG1 – T18-SigG1_r2-r4 region (7), T18-SigG1_SnoaL_2 domain (8); T25-RsfG_N-terminal and T18-SigG1 (9). Results are the average of three independent experiments. Grey bars indicate positive interaction between bait and prey. (c) Co-expression and co-purification of SigG1 and RsfG. SigG1 bound to the 6His-RsfG was eluted with 250 mM imidazole (Ni²⁺E). Immunoblot detection using an antibody against the His-tag (IB1) and a polyclonal antibody anti-SigG1 (IB2). Original uncropped images are presented in Supplementary Fig. S10.