Mapping and sequence of the gene encoding protein p37, a major structural protein of African swine fever virus

The gene encoding protein p37, one of the major structural proteins of African swine fever (ASF) virus has been mapped and sequenced. Protein p37 was obtained from purified virions and the first 27 amino acids from its NH2-terminal end were identified by automatic Edman degradation. To map the gene encoding protein p37, a mixture of 20-mer deoxyoligonucleotides based upon a part of this amino acid sequence was hybridized to cloned ASF virus restriction fragments. This allowed localization of the gene in fragment KpnI F/HindIII G1 of the African swine fever virus genome. An analysis of the DNA sequence from this region revealed an open reading frame encoding 418 amino acids. In this sequence, the 27 NH2-terminal amino acids determined by sequence analysis of protein p37 are preceded by a stretch of 132 amino acids residues, indicating that protein p37 is synthesized as a polypeptide of higher molecular weight and then post-translationally processed by cleavage of a Gly-Ala bond. This processing event accounts for the antigenic relationship of protein p37 to a virus-induced, nonstructural protein with a relative molecular weight of 60 kD.