POSSIBLE RELATION BETWEEN THE U54 SEGMENT OF THE CTHV GENOME AND THE CONSERVED GENE BLOCK-C REARRANGED IN ALPHA AND GAMMA HERPESVIRUS GENOMES

The genome of CTHV is an atypical member of the gamma-2 subgroup of he rpesvirus genomes that contains two segments (instead of one) of DNA w ith low G + C content flanked by highly repetitious DNA with high G C content. The segments freely undergo polarity inversion with respect to one another. We have found nucleotide sequences in one of these se gments, the U54 segment, whose putative translational products show cl ear similarity to two ubiquitous herpesvirus gene products, a single-s tranded DNA binding protein and a protein of the helicase superfamily. These sequences are located within 5 kilobase pairs of the ends of th e segment, suggesting that U54 may be related to a genetically defined entity (gene block C; Davison-and Taylor (1987) J. Gen Virol. 68, 36- 48) issuing from a previous sequence comparison of the gamma-1 genome of Epstein-Barr virus and the alpha genome of varicella-zoster virus.