[Clone of hepatitis B virus X gene and its protein expression].

Objective: To construct the hepatitis B virus (HBV) X gene recombinant and to induce the expression of X protein.

Methods: HBV DNA was extracted from the serum of patient with hepatitis B. The X gene was amplified by PCR using the primers with EcoRI and HindIII digestion sites, and then cloned into pronucleus expression vector pMAL-C2X, which was detected by EcoRI and HindIII digestion and sequence. Finally, the recombinant was induced by IPTG to express X protein in JM109.

Results: The band similar to X gene was amplified by PCR. There were fragments similar to X gene when the recombinant was digested by the enzyme digestion. It was tested by DNA sequence that the correct and entire opening reading frame of HBV X gene was inserted. The X protein was expressed by the IPTG induction.

Conclusion: Pronucleus expression recombinant pMAL-C2X-HBV-X is constructed successfully and with the IPTG induction, the recombinant pMAL-C2X-HBV-X can express the X protein in E. coli JM109, which lays the foundation for the HBV X protein purification and its biological study.