Nucleotide Sequence of a 4 730 Base Pairs Region of the Spodoptera litura Nucleopolyhedrovirus Genome

ZHENG Ji, LI Zhen, LONG Qi-Xin^*, WEI Yong-Jie, WANG Xun-Zhang
( State Key Laboratory for Biocontrol and Institute of Entomology, Zhongsan University, Guangzhou 510275, China )

Abstract    A 4 730 bp region of the Spodoptera litura Nucleopolyhedrovirus genome EcoRI-E fragment was sequenced, in which the odv-e66 gene and other two ORFs, ORF 1086 and the p34 gene, were found. The SpltNPV odv-e66 gene open reading frame was deduced to be 2 079 bp, encoding a protein of 692 amino acids. Unlike odv-e66 genes of AcMNPV and LsNPV, only one transcriptional initiation conserved sequence ATAAG of the late gene was present upstream of the initial codon ATG of SpltNPV odv-e66 gene, and no poly(A) signal was detected at the 3' end of the gene. Four highly conserved regions homologous to those of LdNPV, LsNPV, AcMNPV, BmNPV, CfNPV and OpNPV are present in the amino acid sequence of SpltNPV ODV-E66 protein, with the putative nuclear targeting signal(NTS) KKIWAEDGR in the fourth conserved region. The ORF upstream of the odv-e66 gene had the same direction of odv-e66 gene, but different reading frame. Besides the CAAT box, the early gene regulatory element ACGT and GC motifs and the transcriptional initiation conserved sequence TTAAG of the late gene were present at the 5' end of this ORF. A putative protein of 289 amino acid residues with Mr. about 34 kD was encoded by the ORF, so that it is named P34 protein. A leucine zipper and a leucine zipper-like structure were found in the C- and N-termini of SpltNPV P34 protein respectively. The functions of those regulatory elements may be of great importance to SpltNPV genome. An 1 086 nt open reading frame (ORF) capable of encoding a 361 amino acids polypeptide was found at the 3' end of the odv-e66 gene and in opposite direction. The ORF 1086 protein shares 44% amino acid sequence homology with AcMNPV ORF 109.
Key words Spodoptera litura(Splt) Nucleopolyhedrovirus； odv-e66 gene； ORF 1086； p34 gene

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