The only known gene product is the delta antigen coded for by the large ORF on the minus strand. RNA binding domain 2.nuclear localization signal, which directs the infecting genome and newly synthesized HDAg to the site of viral transcription and replication and 3. A leucine zipper, which is assumed to promote interaction between HDAg and HBsAg in the assembly process. Does not require any helper function for RNA replication. Following entry and uncoating, transported to the nucleus where it utilized RNA polymerase II to transcribe complementary RNA of two distinct forms.
Replication occurs in the nucleus by the double rolling circle model to form large concatemers.
A ligase then closes the circle which is used to make minus strands. During RNA replication of HDV an unusual example of RNA editing is observed. Two main patterns of HDV infection, coinfection and superinfection. Coinfection most commonly result of drug abuse. Both viruses replicate simulataneously.