Core promoter: A critical region where the hepatitis B virus makes decisions

Figure 3 Molecular biology of the hepatitis B virus core promoter. The core promoter (CP) overlaps the 3’-end of the X open reading frame (ORF) and the 5’-end of the pre-C/C ORF. The CP comprises the upper regulatory region (URR) and the basic core promoter (BCP). The former involves a negative regulatory element (NRE) and a core upstream regulatory sequence (CURS) which can be further subdivided into two domains: CURS-A and CURS-B. The sequence of enhancer II and binding sites hepatocyte nuclear factor 1, 3 and 4 (HNF1, HNF3, HNF4) are shown. SPI: S promoter; DR: direct repeat.