ABSTRACT
<p><b>OBJECTIVE</b>To construct a yeast expression vector of hepatitis B virus (HBV) PreS1 gene using the Sos-recruitment system (SRS), and evaluate the effect of the expression product on the growth of the yeast cells and activation of the reporter gene.</p><p><b>METHODS</b>The coding sequence of HBV preS1 was amplified by PCR and cloned into the yeast expression plasmid pSos. The recombinant bait plasmid pSos- PreS1 was verified by sequencing before transformation into competent yeast cells. The effects of the expression product on the yeast cell growth and activation of the reporter gene were evaluated.</p><p><b>RESULTS</b>The yeast expression vector of HBV PreS1 gene was constructed successfully. The recombinant bait plasmid showed no toxic effect on yeast cdc25H cells without a self-activation of the reporter gene.</p><p><b>CONCLUSION</b>The SRS can be used to study the proteins interacting with HBV PreS1 protein and provides a means for obtaining insight into the pathogenic mechanism of HBV.</p>