A novel defective recombinant porcine enterovirus G virus carrying a porcine torovirus papain-like cysteine protease gene and a putative anti-apoptosis gene in place of viral structural protein genes（ウイルス構造タンパクの部分にブタトロウイルスのパパイン様プロテアーゼと推定抗アポトーシス遺伝子を保有する新たな欠損組み替えブタエンテロウイルスG）

Ryo Imai, Makoto Nagai, Mami Oba, Shoichi Sakaguchi, Makoto Ujike, Ruka Kimura, Moeko Kida, Tsuneyuki Masuda, Moegi Kuroda, Rongduo Wen, Kaixin Li, Yukie Katayama, Yuki Naoi, Shinobu Tsuchiaka, Tsutomu Omatsu, Hiroshi Yamazato, Shinji Makino, Tetsuya Mizutani

Enterovirus G (EV-G) belongs to the family of Picornaviridae. Two types of recombinant porcine EV-Gs carrying papain-like cysteine protease (PLCP) gene of porcine torovirus, a virus in Coronaviridae, are reported. Type 1 recombinant EV-Gs are detected in pig feces in Japan, USA, and Belgium and carry the PLPC gene at the junction site of 2C/3A genes, while PLPC gene replaces the viral structural genes in type 2 recombinant EV-G detected in pig feces in a Chinese farm. We identified a novel type 2 recombinant EV-G carrying the PLCP gene with flanking sequences in place of the viral structural genes in pig feces in Japan. The ~0.3 kb-long upstream flanking sequence had no sequence homology with any proteins deposited in GenBank, while the downstream ~0.9 kb-long flanking sequence included a domain having high amino acid sequence homology with a baculoviral inhibitor of apoptosis repeat superfamily. The pig feces, where the novel type 2 recombinant EV-G was detected, also carried type 1 recombinant EV-G. The amount of type 1 and type 2 recombinant EV-G genomes was almost same in the pig feces. Although the phylogenetic analysis suggested that these two recombinant EV-Gs have independently evolved, type 1 recombinant EV-G might have served as a helper virus by providing viral structural proteins for dissemination of the type 2 recombinant EV-G.

Infect Genet Evol.