Characterization of the ecdysteroid UDP-glucosyltransferase gene of a single nucleocapsid nucleopolyhedrovirus of Buzura suppressaria.

A putative ecdysteroid UDP-glucosyltransferase (egt) gene was identified in the single nucleocapsid nucleopolyhedrovirus of Buzura suppressaria (BusuNPV). This is the first egt gene to be characterized in a SNPV, suggesting that egt genes are prevalent in nucleopolyhedroviruses and possibly in all baculoviruses. The open reading frame (ORF) of the gene is 1539 nucleotides (nt) long, encoding a putative protein (EGT) of 513 amino acids (aa) with a M of 58922. The 5' noncoding region contains three possible TATA boxes. A polyadenylation signal, AATAAA, was found downstream of the translation stop codon. A putative signal peptide of 16 residues was present at the N-terminus of the EGT. The BusuNPV egt gene has a high degree of nucleotide and amino acid sequence homology to multiple nucleocapsid (M) NPV egt genes, the highest being to the Spodoptera exigua MNPV egt. A phylogenetic tree of eleven known EGTs was constructed using maximum parsimony analysis.