DNA-binding and transcriptional activities of DREB2C. A, DNA-binding activity of DREB2C was determined by electrophoretic mobility shift assay. Oligonucleotides containing DRE, mutant DRE (mDRE), Cor15a promoter fragment, or mutant Cor15a fragment were employed as probes. The wild-type and mutant DRE/CRT core sequences in probe DNA are indicated by boldface. −, Probe without recombinant DREB2C; +, probe with recombinant DREB2C. B, Transcriptional activity of DREB2C. Transcriptional activity of DREB2C was determined employing a yeast assay system, as described in “Materials and Methods.” The various portions of DREB2C used in the assay are shown schematically at the bottom. GBT9, Empty vector without any insert; DREB2C-Full, full-length DREB2C; DREB2C-N, N-terminal portion of DREB2C; DREB2C-AP2, AP2 region of DREB2C; DREB2C-C, C-terminal portion of DREB2C. The numbers in parentheses indicate amino acid positions. The values represent β-galactosidase activity in Miller units, and the error bars denote se (n = 5 each).