Figure 3.

A proposed model of HBx mediated cccDNA minichromosome epigenetic modulation. (A) In the absence of HBx, cccDNA-bound histones are hypoacetylated and the host restriction factors are recruited on the cccDNA, contributing to repressed gene transcription and viral replication. (B) In the presence of HBx, HATs are recruited to cccDNA and host restriction factors, such as PRMT1, EZH2, SETDB1 and Smc5/6, are inhibited by HBx, leading to hyperacetylation of cccDNA-bound histones and active cccDNA transcription.