Molecular cloning and physical mapping of the genome of simian herpes B virus and comparison of genome organization with that of herpes simplex virus type 1.

The molecular structure of the genome of simian herpes B virus (SHBV) was determined by restriction endonuclease mapping studies. Genomic DNA was cleaved with restriction endonucleases BamHI and SalI into 41 and 58 fragments, respectively. Most of these fragments were cloned into the plasmid vector pACYC184; uncloned fragments were identified following isolation from agarose gels. Terminal fragments were identified by exonuclease digestion and radioactive end-labelling, and linkage of fragments was deduced by a combination of single and double digest experiments and cross-blot hybridizations. The genome is larger than that of herpes simplex virus type 1 (HSV-1), being approximately 165 kilobase pairs. Like that of HSV-1, the SHBV genome is composed of a long and a short unique region each flanked by inverted repeat sequences, which allow the unique regions to invert relative to one another, resulting in four possible isomeric arrangements of the molecule. Genome locations of several SHBV genes were compared with their HSV-1 homologues.