FIG. 1.
Functional region of the 2-18 polymerase gene (open bars), HBV region flanking the polymerase gene of 2-18 (checkered bars), functional region of the 56 polymerase gene (shaded bars), and HBV region flanking the polymerase gene of 56 (stippled bars). 2-18P56, 2-18SP56, 2-18TP56, 2-18RNaseH56, and 2-18RT56 are 2-18 chimeric genomes in which the complete P gene or each of the functional regions of the P gene, namely, spacer, TP, RNase H, and RT, was replaced with either the complete P gene or each of its counterparts from 56. 56RT2-18 is a 56 HBV chimeric genome in which the RT region of the P gene was replaced with its 2-18 counterpart.