FIG. 2.

Replicative cycle of members of the Flaviviridae. The presumed replication cycles of the hepaciviruses and pestiviruses (A) and of the flaviviruses (B) are shown. 1, adsorption; 2, receptor-mediated endocytosis; 3, low-pH fusion in lysosomes; 4, uncoating; 5, IRES-mediated initiation of translation (A) or cap-mediated initiation of translation (B); 6, translation of the viral RNA into viral precursor polyprotein; 7, co- and posttranslational proteolytic processing of the viral polyprotein by cellular and viral proteases; 8, membrane-associated synthesis of template minus-strand RNA and progeny plus-strand RNA; 9, assembly of the nucleocapside; 10, budding of virions in the endoplasmatic reticulum; 11, transport and maturation of virions in the endoplasmatic reticulum and the Golgi complex; 12, vesicle fusion and release of mature virions. ss, single stranded.