FIGURE 2.

Purified MeCP2 is a potent CG-methylation-specific repressor of transcription. Shown is transcriptional repression by purified full-length MeCP2. CG-methylated or unmethylated pUC-SCP-8CG template DNAs were transcribed with HeLa nuclear extract either in the absence of MeCP2 or in the presence of the indicated concentrations of wild-type MeCP2. At 500 nm MeCP2, there is approximately one molecule of MeCP2 per CG dinucleotide in the pUC-SCP-8CG template. The resulting transcripts were subjected to primer extension analysis. The image is a continuous single exposure of a series of reactions that were performed in parallel with equivalent amounts of methylated or unmethylated template DNA. The relative activity values are normalized to the amount of transcription observed in the absence of MeCP2.