background: hepatitis delta virus (hdv) is a subviral human pathogen that exploits host rna editing activity to produce two essential forms of the sole viral protein, hepatitis delta antigen (hdag). editing at the amber/w site of hdv antigenomic rna leads to the production of the large form (l-hdag), which is required for rna packaging. methods: in this study, pcr-based site-directed mutagenesi...