Cloning，Sequence Analysis and Expression in E.coli of the EP0 Gene of Pseudorabies Virus Ea Strain / 中国病毒学

ABSTRACT

The 1.23 kb DNA fragment encoding the early protein EP0 of pseudorabies virus (PRV) Ea strain was amplified by PCR technique and cloned into pBluescriptII sk+.Three sequencing plasmids containing the partial fragment of the EP0 gene were constructed and the sequences were obtained by Sanger's sequencing technique. Compared with PRV InFh strain, there were multipile site-mutations and a deleted-mutation in the EP0 gene of PRV strain Ea，and the diversity of amino acid residues also existed.Then, the EP0 gene was inserted into an expression vector, pET-28a, fused into the downstream of the 6ΧHis-Tag in frame, to yield the expression plasmid pETEP0. After induction by IPTG, a high expression of fusion protein was obtained, SDS-PAGE analysis and Western blotting showed that the fusion protein was 62kD and the protein was specific to antisera against PRV Ea strain. This indicated that the EP0 gene be expressed in BL21(DE3) and the expression products have immuno-genicity.