FMDV 3D Gene Cloning Expression and Functional Analysis

he RdRp gene of Foot-and-mouth disease virus was amplified by reverse transcription polymerase chain reaction (RT-PCR) using pfuultraTM High-Fidelity DNA polymerase, and was then cloned into the prokaryotic expression vector pET-28a (+). E.coli BL-21 cells were transformed with the recombinant plasmid and the target protein was expressed in soluble form. The purified recombinant protein was confirmed to be expressed correctly by Western-blotting. The RNA in vitro replication assay was used to determine the high activity of purified RdRp. The product of replication system was quantified by strand-specific real-time RT-PCR. These results suggested that the purified RdRp could initiate the de-novo RNA synthesis but was mainly in a primer-dependent manner, which shows high activity of RNA-dependent RNA polymerase. The Vpg protein primer can dramatically improve the capacity of RNA synthesis.