FIG. 7.

Identification of a point mutation in clone 4B that inhibits virion secretion. (A) Cartoon view of the constructs. The inhibitor of virion secretion is located in the AvrII (179-to-520) region, which contains four nucleotide changes. Since the T552C mutation can suppress the inhibitory mutation, constructs in this series all had the wild-type fragment 520-730 sequence. Construct N49 was derived from N43 by reversion of position 484 back to T; construct N50 differs from N44 by a T484G mutation. (B) HBV DNA replication inside transfected cells and virion secretion into the culture medium. DS, double-stranded DNA; SS, single-stranded DNA; HBV, 3.2-, 1.7-, and 1.4-kb HBV DNA. Also shown are HBsAg and HBeAg values from culture supernatants of transfected Huh7 cells (diluted 13-fold for results shown on the left and 25-fold for HBsAg values shown on the right).