Fig. 5.
LqqP-PcoI interactions. (A) B2H assay shows the interaction between LqqP and PcoI. pTRG-PcoI and pBT-LqqP were co-expressed in E. coli XL1-blue. “+”, positive control – co-expression of plasmids pBT-GacS and pTRG-GacS [33]; “-”, negative control – co-expression of empty pTRG and pBT vectors. (B) Pull-down assay to confirm the interaction between PcoI-His and GST-LqqP. Immunoprecipitation was performed using anti-GST antibody. Western blot was performed by using anti-GST and anti-His antibodies. (C) MST measurement of binding affinity: green trace, between PcoI-His and His-TF-LqqP (Kd, 0.64 μM); red trace, between PcoI-His and His-TF (no binding). TF, trigger factor - a prokaryotic ribosomal binding partner protein that can induce co-translational folding of new peptide chains. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)