Figure 1.

HBV structure and genome. (A) The envelope of HBV virion consists of lipids and the large, medium, and small viral surface proteins. Within the lumen of the virus, core protein forms an icosahedral capsid around the rcDNA genome which has the viral polymerase covalently attached to the 5′ end of the (−) strand and a capped RNA primer (red) attached to the 5′ end of the (+) strand. (B) The 3.2 kb HBV genome encodes four overlapping ORFs (Pre-Core/Core (Pre-C/C), Polymerase (P), Pre-S1/Pre-S2/S, and X) and four mRNA transcripts with an overlapping 3′ end (3.5 kb, 2.4 kb, 2.1 kb, and 0.7 kb).