Expression and purification of a functional human hepatitis B virus polymerase

Figure 1 Organization of pTrcHis-A-Pol and pT7-Pol recombinant plasmids. A: Structural arrangement of pTrcHis-A-Pol. A full-length hepatitis B virus polymerase (HBV-Pol) sequence was fused into pTrcHis-A between NotI and BstBI sites under the control of Trc promoter and Lac operator. This polyhistidine tag plays a role in rapid purification using a nickel-based resin. To determine the expression level under different conditions, an Xpress antigen was fused to the 5’-end of the HBV-Pol sequence; B: Structure of pT7-Pol. A full-length HBV-Pol sequence was fused to P-T7 between NotI and BstBI sites. Full-length HBV-Pol sequence was under the control of the T7 promoter for expression in the TNT T7 transcription–translation-coupled rabbit reticulocyte lysate expression system.