FIG. 1.

Structures of the baculovirus-expressed HBV transcripts used to generate nucleocapsids. The core (C) and Pol (P) ORFs are indicated (shaded boxes). ECPE carries a full-length pregenome-like HBV insert flanked by HBV regulatory sequences harboring the ɛ stem-loop structure (E); ECP, CPE, and CP are ECPE derivatives lacking, respectively, the 3′ DR1 and ɛ element (ECP), 5′ ɛ (CPE), or both (CP). Note that DR1 is included with the 3′ but not the 5′ ɛ element in these RNAs. EC and C encode the core protein only and are similar except only the former harbors the 5′ ɛ; likewise, PE and P are both monocistronic Pol mRNAs which differ by the inclusion of the 3′ DR1 and ɛ element in PE. Shown for all the RNAs are the polyadenylated 3′ ends (AAA) and the short (120-bp) 5′ baculovirus-derived leader sequence (dotted line at the 5′ end).