10.1371/journal.pone.0072798.g001 Hui Feng Hui Feng Ping Chen Ping Chen Fei Zhao Fei Zhao Michael Nassal Michael Nassal Kanghong Hu Kanghong Hu Key roles of the P protein - ε RNA interaction in HBV replication. Public Library of Science 2013 Biochemistry Nucleic acids rna microbiology Virology Viral replication Viral nucleic acid Viral packaging Viral replication complex Viral enzymes Gastroenterology and hepatology Liver diseases Infectious hepatitis Hepatitis B hbv 2013-08-20 01:38:13 Figure https://plos.figshare.com/articles/figure/_Key_roles_of_the_P_protein_949_RNA_interaction_in_HBV_replication_/777051 <p>The line with the hairpin structures represents the terminally redundant pgRNA which also serves as mRNA for core protein and P protein; ε and the direct repeats DR1, DR2 and DR1* are indicated. Binding of P to ε initiates their co-encapsidation, and also protein-primed reverse transcription. In this priming reaction, the 3′ nucleotide of the ε bulge and/or the first nucleotide of the upper stem (termed A1 in this study) template the covalent addition of the first DNA nucleotide to a Tyr residue in the TP domain (not explicitly shown) and its extension by two or three nucleotides along the bulge. Upon translocation to a matching acceptor site in DR1* the oligonucleotide is extended into full-length minus-strand DNA, with concomitant degradation of the pgRNA. Subsequent plus-strand synthesis (not shown) eventually yields the relaxed circular (RC) DNA found in virions. The differing shapes of ε and P symbolize conformational alterations that are as yet only well established for DHBV.</p>