Nucleotide sequence and in vitro expression of rubella virus 24S subgenomic messenger RNA encoding the structural...

The complete nucleotide sequence of the 24S subgenomic mRNA of wild-type M33 strain rubella virus has been determined. This RNA is 3,383 nucleotides in length excluding the 3'-terminal poly(A) tract. After the three multiple in-phase termination codons clustered in the 5' terminus of this RNA, there are 81 nucleotides of nontranslated nucleic acid followed by a reading frame of 2,978 nucleotides that encodes the 110 kD precursor of the structural proteins. The 3'-untranslated region is 263 nucleotides. The 110 kD polyprotein is processed to produce nucleocapsid C, the glycoproteins E2 and E1 in that order. Sites of post-translational cleavage to produce E2 and E1 were located using available N-terminal amino acid sequences. RNAs synthesized by transcription in vitro are effective messengers in the rabbit reticulocyte cell-free translation system. Post-translational processing of the structural proteins was observed in the cell-free system supplemented with microsomes from dog pancreas.