Sequence analysis of the Xestia c-nigrum granulovirus genome.

The nucleotide sequence of the Xestia c-nigrum granulovirus (XcGV) genome was determined and found to comprise 178,733 bases with a G+C content of 40.7%. It contained 181 putative genes of 150 nucleotides or greater that showed minimal overlap. Eighty-four of these putative genes, which collectively accounted for 43% of the genome, are homologs of genes previously identified in the Autographa californica multinucleocapsid nucleopolyhedrovirus (AcMNPV) genome. These homologs showed on average 33% amino acid sequence identity to those from AcMNPV. Several genes reported to have major roles in AcMNPV biology including ie-2, gp64, and egt were not found in the XcGV genome. However, open reading frames with homology to DNA ligase, two DNA helicases (one similar to a yeast mitochondrial helicase and the other to a putative AcMNPV helicase), and four enhancins (virus enhancing factors) were found. In addition, several ORFs are repeated; there are 7 genes related to AcMNPV orf2, 4 genes related to AcMNPV orf145/150, and a number of repeated genes unique to XcGV. Eight major repeated sequences (XcGV hrs) that are similar to sequences found in the Trichoplusia ni GV genome (TnGV) were found. Copyright 1999 Academic Press.