ABSTRACT
The extremely small Asfuvirales order currently includes a sole family Asfarviridae with the sole genus Asfivirus involving the only recognized African swine fever virus species, well-known because of its ecological and economical danger. African swine fever virus (ASFV) is the only virus with the double-stranded DNA genome, which is transmitted by arthropods. In 2019–2020, the near-atomic ASFV structure was resolved by electron cryomicroscopy in parallel by three advanced teams. The multilayered ASFV structure is described, including the nucleoprotein core structure, 70–100 nm in diameter, surrounded by an internal lipid layer and an icosahedral capsid, 170–190 nm in diameter, which in turn is eventually surrounded by an external lipid-containing envelope, with a diameter of 175–215 nm. A special attention is devoted to the inner protein layer, organized as a T = 19 icosahedron. The mutant ASFV virions are described, which change viral morphogenesis from icosahedral to filamentous particles. The expression of the ASFV genes in E. coli, baculovirus, and yeast expression systems is presented, although all attempts did not pretend to produce any kind of the ASFV VLPs. In opposite, the chimeric infectious ASFV virions were engineered via fusion of the foreign epitopes with the ASFV p54 protein.
