Biosynthesis of reovirus-specified polypeptides. Molecular cDNA cloning and nucleotide sequence of the reovirus serotype 1 Lang strain s3 mRNA which encodes the nonstructural RNA-binding protein sigma NS.

Human reovirus serotype 1 Lang strain s3 mRNA, which encodes the nonstructural RNA-binding polypeptide sigma NS, was cloned as a cDNA:mRNA heteroduplex in Escherichia coli using phage M13. A complete consensus nucleotide sequence was determined. The Lang strain s3 mRNA is 1198 nucleotides in length and possesses an open reading frame with a coding capacity of 366 amino acids, sufficient to account for a sigma NS polypeptide of 41,179 daltons. Comparison of the serotype 1 (Lang) s3 sequence with the serotype 3 (Dearing) s3 sequence reveals 86.8 percent homology at the nucleotide level. The predicted sigma NS polypeptides of the Lang and Dearing strains display 97 percent homology at the amino acid level.