Oligomerization of hepatitis delta antigen is required for both the trans-activating and trans-dominant inhibitory activities of the delta antigen.

摘要: Abstract Two forms of hepatitis delta antigen (HDAg) have different roles in the replication cycle virus (HDV); small trans activates HDV RNA replication, whereas large form suppresses it but is needed for virion assembly. To understand mechanism these regulatory activities, we studied possible HDAg oligomerization and its role replication. In this report, provide direct biochemical evidence vitro vivo formation homodimers heterodimers between two species. By deletion mutagenesis, showed that protein interaction mediated by leucine zipper-like sequence residing N-terminal one-third HDAg. Furthermore, site-specific mutants with various substitutions on residues stretch had reduced or no ability to dimers. Correspondingly, mutations abilities activate Similar also resulted loss inhibit The biological activities both (trans activation trans-dominant inhibition respectively) correlated extent vitro. Thus, conclude participates as an oligomer inhibits a result complex A "black sheep" model presented.