Table 1

HBV ORFs and proteins

ORFProteinFunction/role in pathogenesis of HBV infection
PViral polymeraseDNA polymerase, reverse transcriptase, and RNase H activity; contains functional domains essential for encapsidation of the pregenomic RNA
SHBV surface proteinsPre-S1 protein plays a key role in attachment of the virus to the hepatocyte (200)
CCore proteinForms the capsid and encapsidates HBV nucleic acids
HBeAgBiological role is poorly understood; however, strong epidemiological associations between HBeAg and HBV DNA level (53) and the risk of progression to hepatocellular carcinoma (290) are well documented
XHBx proteinTransactivator of viral regulatory elements and host gene promoters (60, 248), essential for establishment of infection in vivo (300), potential role in hepatocarcinogenesis (60)