Conformational plasticity of the intrinsically disordered protein ASR1 modulates its function as a drought stress-responsive gene
Fig 4
A) Description of full-length FRET reporters. B) Illustration of single tagged-ASR1 constructs. C) Diagram of possible events that may modify FRET efficiency of the ASR1 sensor. D) Fluorescent spectra of purified sticky and non-sticky reporter proteins in the presence or absence of 1 mM Zn2+. E) In vitro Zn2+ titration (1 μM protein) in low micromolar and nearly millimolar ranges (inset) for sticky (circles), non-sticky (triangles) and equal amounts of both single-tagged proteins (stars). Relative (Idonor/IIsosbestic) ratios are shown. Lines correspond to the best fit to Eq 5 for the low micromolar range and Eq 7 for nearly micromolar range. F) NaCl-induced stress assays in E. coli cells expressing sticky (circles) or non-sticky probes (triangles). Relative (Idonor/IIsosbestic) ratios as a function of NaCl concentration are shown.