SlHsfA3 directly binds to the promoter regions of SlHsp26.1-P and SlHsp21.5-ER.

(A) Illustration of the SlHsp26.1-P and SlHsp21.5-ER promoter regions showing the presence of HSEs DNA motifs. HSEs are drawn according to the nomenclature of Nover et al. (2001) [3]. Numbers in between indicate the distance in bp. The TATA box is also indicated in the schematic diagram. (B) EMSA assays showing that SlHsfA3 binds the HSEs motifs present in the SlHsp26.1-P and SlHsp21.5-ER promoters in vitro. SlHsfA3-MBP recombinant protein was expressed in E. coli cells. The corresponding probes were indicated in (A) and labeled with biotin. Competition for SlHsfA3 binding was performed with 10X, 20X and 50X cold unlabeled probes and 20X mutated probes. For details see Materials and methods.