Sequence determination and analysis of the full-length genome of Colorado tick fever virus, the type species of genus Coltivirus (family Reoviridae)

The Colorado tick fever virus (CTFV) is the type species of genus Coltiviru s, family Reoviridae. Its genome consisting of 12 segments of dsRNA was com pletely sequenced. It was found to be 29,174 nucleotides long (the longest of all Reoviridae genomes characterized to date), Conserved sequences at th e 5' end (SACUUUUGY) and at the 3' end (WUGCAGUS) of the 12 segments were i dentified. The analysis of the putative proteins deduced from the nucleotid e sequences permitted to identify functional motifs. In particular, the VP1 was identified unambiguously as the viral RNA dependent RNA pylmerase (RDR P) (VP1pol), with a GDD located at a similar position to Reoviridae RDRPs. In other genes, RGD cell-binding, NTPAse, single strand binding protein and kinase motifs were identified. Comparison with Reoviridae proteins showed significant similarities to RDRPs (CTFV-VP1) and sigma C protein of orthore ovirus (CTFV-VP6). Similarities to nonviral enzymatic proteins, such as met hyltransferases, NTPAses, RNA replication factors,were also identified. (C) 2000 Academic Press.