Transcription of EBV immediate-early (IE) genes. (A) The locations of two immediate-early (IE) genes, BZLF 1 and BRLF1, the two IE promoters, Zp and Rp, are shown. (B, C) Schematic drawing of the structure of Zp and Rp including the distribution of CpG sites, transcriptional elements and the location of analyzed MSP sites and BGS region. HI: the multiply repeated sequence motif. ZI, ZII and ZIII: three positive regulatory cis-acting elements. ZI motifs (ZIA, ZIB, ZIC, and ZID): AT-rich sequences. ZRE: Zta-response element. Shadowed region in Zp indicates a region not methylated in any sample. Shadowed region in Rp indicates the binding site for Zta.