Physical map and polyhedrin gene sequence of Lymantria dispar nuclear polyhedrosis virus

Abstract

Restriction maps of the 166.6-kb genome of Lymantria dispar multiply-enveloped nuclear polyhedrosis virus (LdMNPV clone g) were constructed for BamHI, BglII, EcoRI, EcoRV, HindIII and KpnI, using cosmid pVK102 and pBluescript vectors. Southern hybridizations indicated that the LdMNPV genome contains five dispersed regions of intragenomic sequence homology. The polyhedrin gene of LdMNPV was located within BglII-E and the sequence of the 735-nucleotide (nt) coding region and 678 nt of flanking DNA was determined. A conserved 14-nt sequence, associated with transcriptional start points in other polyhedrins, was identified at 44 to 57 nt upstream from the start codon. The deduced polyhedrin amino acid (aa) sequence showed a high degree of homology with a previously determined protein sequence for LdMNPV polyhedrin (89%) and with deduced amino acid sequences for three other MNPV polyhedrins (74%). Optimal alignment of the four sequences indicated that LdMNPV polyhedrin possesses a single aa insertion at residue 4 and a single aa deletion at residue 164.