Expression and purification of SARS nucleocapsid protein in saccharomyces cerevisiae

Objective To construct recombinant plasmid with nucleocapsid gene,and to induce the expression of nucleocapsid protein in saccharomyces cerevisiae.Methods The SARS-CoV DNA fragment was produced by the way of reverse transcription and two overlapped fragments of SARS nucleocapsid gene were obtained by RT-PCR and ligated to form an integrity nucleocapsid gene.The nucleocapsid gene was recombined with pYES6 and cloned in E.coli JM109.The recombinant plasmid pYES6-N was induced to express in saccharomyces cerevisiae and then purified.Results The size,direction and base matching of the inserted fragment were in accordance with our expectation,which was determined by the restriction and sequencing on recombinant plasmid pYES6-N and suggestive of an integrity nucleocapsid gene.The expression product of the gene was approximate 45 000 after being purified and identified by protein electrophoresis.Conclusion Successful clone of an integrity SARS-CoV nucleocapsid gene and its effective expression in saccharomyces cerevisiae can be beneficial to the research on SARS vaccine.