RAP2.1 binds to DRE and acts as a transcriptional repressor. (A) Schematic representation of the RAP2.1 amino acid sequence. A nuclear localization signal (NLS), AP2 DNA-binding domain (AP2), a putative acidic domain (Acidic) and the conserved valine (V) and glutamic acid (E) residues are indicated. The key residues of the EAR-motif without (wEAR-motif) or with site-mutation (mEAR-motif) are also shown. (B) RAP2.1 binding to the DRE element. The oligo-nucleotide probes of wild type DRE (wDRE) and mutated DRE (mDRE) used in gel shift assay are listed. DNA probe alone (100 ng) or incubated with 5 μg or 10 μg of recombinant protein were assayed. FP: free probes; B: DNA-protein complex. (C) Diagram of reporter and effector constructs. Ω, translational enhancer of tobacco mosaic virus; Nos, terminator signal of the gene for nopaline synthase. (D) Repression of reporter gene activity by RAP2.1 and suppression of DREB1A-mediated transactivation by RAP2.1. Values shown are means of data taken from three independent experiments; error bars indicate SD.