Nucleotide sequence and transcript mapping of the HindIII F region of the Autographa californica nuclear polyhedrosis virus genome.

The organization of genes in the 2.95 kb EcoRI-SalI fragment (0.7 to 3.0 map units) located within the HindIII F region of the Autographa californica nuclear polyhedrosis virus genome was studied by a combination of DNA sequencing, Northern blot analysis, S1 mapping and primer extension analysis. In addition to the two divergent overlapping transcripts [leftward early (ES1) and rightward late (ES2)] previously reported, a third transcript which is present at 18 h p.i. and which also runs leftward, overlapping ES1 by 1600 nucleotides (nt) at the 3' end, was mapped to this region. The DNA sequence revealed the presence of three open reading frames (ORFs) of significant length. ORF-1 and ORF-2 correspond to the leftward transcripts, and code for potential polypeptides of 151 and 329 amino acids, respectively. ORF-3 which codes for a potential polypeptide of 167 amino acids is located on the opposite strand in a region for which no transcript mapping data are available. However, the conserved late gene promoter/cap site sequence (ATAAG) is present 23 nt upstream of the start of ORF-3.