THE UL6 LOCUS OF PSEUDORABIES VIRUS AND ITS HOMOLOGY TO ONCOGENIC HERPESVIRUSES

The UL6 locus of pseudorabies virus (PRV) was analyzed to reveal a gen e cluster with homology to herpes simplex virus UL5, UL6, UL7 and UL8, Epstein-Barr virus BBRF1 and BBRF2, and Kaposi sarcoma-associated her pes virus ORF43 and ORF42. The noncoding region between PRV UL7 and UL 8 contained 16 copies of a 14 bp T + C-rich repeat element. The mRNA s tart sites for UL6 and UL7 were mapped by primer extension and UL6 was expressed in vitro. The mobility of the in vitro-expressed UL6 protei n correlated with the predicted mass of 66 kDa. The relationship and p otential significance of the UL6 locus with the corresponding sequence s in oncogenic herpesviruses is discussed.