Bidirectional transcription of maize streak virus DNA and identification of the coat protein gene.

Three RNA transcripts encoded by maize streak virus DNA were detected in polyadenylated RNA from virus-infected maize leaves. Two of the transcripts, a major 0.9 kb and a minor 1.05 kb RNA, were mapped on the virion (+) sense DNA and the other minor transcript of 1.2 kb was mapped on the complementary (-) sense DNA, demonstrating that transcription of MSV DNA was bidirectional. The two virion sense transcripts were 3' coterminal at nucleotide 1114 but had 5' termini at nucleotides 2682 and 163 respectively. Virus-specific polyadenylated RNA translated in vitro to produce a 28,000 MW polypeptide, specifically immunoprecipitable by antiserum raised against whole virus. The mRNA for this protein was mapped by hybrid-arrested translation to the long open reading frame in virion sense DNA whose potential amino acid composition, calculated from nucleotide sequence data, closely agreed with that determined experimentally for the coat protein.