Nucleotide sequence of gene 6 of avian-like group A rotavirus 993/83.

Two cDNA clones, which hybridized in Northern blots to RNA segment 6 of the homologous avian-like group A rotavirus (RV) 993/83 and pigeon RV PO-13, but not to mammalian group A rotaviruses, were sequenced. The gene 6 sequence contained a single long open reading frame encoding a protein of 397 amino acids (total MW 44,460). Comparison of the deduced amino acid sequence with VP6 protein from mammalian group A RV revealed 72 to 74.3% of amino acid identity. These values are surprisingly low in view of the high homology levels described up to now for group A RV. Avian-like RV 993/83 is however not a missing link between group A and C RV as it is as distantly related to group C RV as group A mammalian RV to group C RV. The evolutionary implications of these observations are briefly discussed.