The UL6 locus of pseudorabies virus and its homology to oncogenic herpesviruses.

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