NUCLEOTIDE-SEQUENCE OF THE POLYHEDRIN GENE REGION OF HELICOVERPA-ZEA SINGLE NUCLEOCAPSID NUCLEAR POLYHEDROSIS-VIRUS - PLACEMENT OF THE VIRUS IN LEPIDOPTERAN NUCLEAR POLYHEDROSIS-VIRUS GROUP-II

The polyhedrin gene (polh) of Helicoverpa tea single nucleocapsid nucl ear polyhedrosis virus (HzSNPV) was identified and shown by sequence a nalysis of the EcoRI I genomic fragment to encode a 246 amino acid pol ypeptide that has greater than 80% sequence identity to known polyhedr ins. It is preceded by an AT-rich region containing the conserved late promoter motif TAAG, which was identified as a transcription start po int. Downstream of polh there were several similarities in genome arra ngement to other nuclear polyhedrosis viruses (NPVs). These include op en reading frame (ORF) 8, immediately downstream of polh, encoding a 4 12 amino acid protein with multiple tandem proline residues, which is homologous to ORF8 (ORF1629) of Autographa californica multiple nucleo capsid NPV. Phylogenetic analysis of the polh gene region shows that H zSNPV is a member of the previously described lepidopteran NPV group I I and that it is most closely related to polh of the NPVs of Malacosom a nuestria, Spodoptera littoralis, Orgyia pseudotsugata (single nucleo capsid-type virus) and Buzura supressaria.