Sequence Analysis And Bacterial Expression Of ORF34 And ORF44 From Helicoverpa Armigera Nucleopolyhedrovirus

As an organism exclusively pathogenic to the cotton bollworm, Helicoverpa armigera, nucleopolyhedrovirus (HearNPV) can serve as an ideal biological control agent. The genomes of HearNPV G4 and C1 isolates have been completely sequenced. Several genes in HearNPV have been characterized, but the functions of many ORFs remain unknown. ORF34 and ORF44 were primarily analyzed in this paper, and the results showed that ORF34 and ORF44 were unique to HearNPV among NPVs and the expression of fused ORF34 and ORF44 proteins provided the basic information on the analysis of their functions.HearNPV ORF34 is 1080 nt long ,encoding a putative protein of 359aa with a predicted size of 41.2 kDa. Three baculovirus consensus early promoter motifs are found in ORF34. One transmembrane helices region, as well as 15 putative phosphorylation sites and one N-linked glycosylation site are found in the predicted ORF34 protein. No homologue that shares an identity over 30% through NPVs and GVs was found in GenBank and SWISS-PROT . A pET-34 plasmid was constructed and ORF34 was expressed in the E.coli (BL21). The molecular weight of expressed fusion protein is 42 kDa, which is in tune with the predicted size. The results show that ORF34 is unique to HearNPV among NPVs, and the expression of fused ORF34 protein provides the basic information on the functional analysis of HearNPV ORF34.HearNPV ORF44 is 1137 nt long ,encoding a putative protein of 378aa with a predicted size of 42.7 kDa. Both baculovirus consensus early and late promoter motifs are found in ORF44. One transmembrane helices region, as well as 32 putative phosphorylation sites and 4 N-linked glycosylation sites are found in the predicted ORF44 protein. No homologue that shares an identity over 30% through NPVs and GVs was found in GenBank and SWISS-PROT . A pET-44 plasmid was constructed and ORF44 was expressed at high level in the E.coli (BL21). The molecular weight of expressed fusion protein is 44 kDa, which is consistent with the predicted size. The results show that ORF44 is unique to HearNPV among NPVs, and the expression of fused ORF44 protein facilitates the preparation of anti-ORF44 polyclonal antiboby to the further analysis of its function.