The complete cDNA sequence of a type II Trichomonas vaginalis virus

Trichomonas vaginalis viruses (TVV), which may regulate P270 gene expressio n in the protozoan pathogen T: vaginalis, are a group of divergent double-s tranded (ds) RNA viruses. In the present study, the complete 4674-bp cDNA s equence of a 4.6-kb ds RNA from a newly identified TVV2-1 isolate was deter mined. The sequence of the plus-strand mRNA contains four open reading fram es, which encode overlapping cap and pol genes in the reading frame 2 and r eading frame 1, respectively, and two putative serine-threonine-rich basic proteins VP3 and VP4 in the third reading frame. An 85-kDa capsid protein a nd a 180-kDa CAP-POL fusion protein were identified in crude viruses by Wes tern blotting experiments using antisera raised against gene-specific oligo peptides. In conjunction with the presence of a potential ribosomal slipper y heptanucleotide G GGC CCC within the overlap of the cap and pol genes, th ese observations suggest that the pol gene of TVV2-1 is translated via a -1 ribosomal frameshifting event during translation of the cap gene. Our resu lts also provide insight into the conservation among divergent dsRNA specie s from TW and suggest that the genome of TVV2-1 may encode two extra genes in addition to the cap and pol genes. (C) 2000 Academic Press.