X region mutations of hepatitis B virus related to clinical severity

Figure 1 Hepatitis B virus-X protein genome structure. The HBV X region contains 465 bp (nt 1374 to 1838) encoding the 16.5 kDa HBx protein composed of 154 aa, which also contains several critical cis-elements such as EnhII (nt 1636 to 1744), the core promoter (nt 1613 to 1849) and the microRNA-binding region (nt 1362 to 1383). Thus, HBx mutations affected not only the HBx open reading frame but also the overlapped cis-elements. HBx: Hepatitis B virus-X protein.

Figure 2 Mapping of deletions or insertions in the hepatitis B virus-X protein region. Deletions or insertions in the HBx region mainly occur in the C-terminal region of HBx, which may also contribute to the clinical outcome severity in chronic patients. HBx: Hepatitis B virus-X protein.