Mutating the DHBV P RNAseH domain yields an RNAseH deficient phenotype. DHBV viral cores were produced in LMH cells transfected with wild-type DHBV DNA or DHBV DNAs carrying mutations in the P gene (D715V in the RNAseH domain or YMHA in the reverse transcriptase domain). Viral DNA was isolated by proteinase K digestion, phenol and chloroform extraction, and ethanol precipitation. Viral DNAs were detected by Southern analysis with strand-specific riboprobes covering DHBV nt 170-3021; the left panel shows negative-polarity DHBV DNAs and the right panel shows positive polarity DNAs. DHBV monomer DNA is a 3021 bp EcoRI monomer of cloned DHBV DNA, RC DNA is mature relaxed circular DNA, DL DNA is duplex linear DNA, SS DNA is full-length single-stranded DNA.