Maize stripe virus RNA5 is of negative polarity and encodes a highly basic protein.

The entire 1317 nucleotide sequence of the maize stripe virus (MStV) RNA5 was determined. Only one open reading frame (ORF) was identified and was found in the viral complementary RNA (vcRNA). This ORF appears to encode a protein of M(r) 44237, hereafter referred to as NS5 delta. In vitro translation of transcripts representing nearly full-length RNA5 vcRNA yielded products of the predicted size, as well as some smaller, less prominent products. No products were identified from transcripts of viral polarity. RNA hybridization analyses of MStV-infected Zea mays revealed RNAs corresponding only to full-length RNA5, but both positive and negative polarity RNAs were abundant. Analysis of the NS5 amino acid sequence revealed that it is extremely basic, containing 21% arginine and lysine. Database comparisons showed that NS5 had no significant similarity to other protein sequences.