SEQUENCING OF A 5.5-KB DNA FRAGMENT AND IDENTIFICATION OF A GENE CODING FOR A SUBUNIT OF THE HELICASE PRIMASE COMPLEX OF AVIAN LARYNGOTRACHEITIS VIRUS (ILTV)/

The nucleotide sequence of a 5,520-bp EcoRI restriction fragment of av ian infectious laryngotracheitis (ILTV) DNA was reported and submitted to GeneBank with an accession number of AF001078. Computer prediction revealed one large potential open reading frame (ORF) with sequence s imilar to one subunit of the DNA helicase-primase complex of alpha-her pesviruses. The DNA helicase/primase complex of HSV-1 consists of thre e sub-units with molecular weights of 12,000, 97,000 and 70,000, encod ed by genes UL52, UL5 and UL8, respectively. This enzyme complex is es sential for herpesvirus DNA replication. The UL52 and UL5-equivalent g enes of ILTV have been reported previously (Fuchs, W. and Mettenleiter , T.C., J Gen Virol, 1996, 77: 2221-2229; Johnson, M.A. et. al., Arch Virol, 1995, 14: 623-634). Amino acid sequence comparison and homology search revealed that this ORF shares sequence similarity to the UL8-e quivalent gene of cr-herpesviruses, that is, the ORF 52 of vericura-zo ster virus (VZV), the ORF 54 of equine herpesvirus type-1 (EHV-1), as well as the equivalent gene of bovine herpesvirus type 1 (BHV-1) and c anine herpesvirus (Vlcek, C. et al., Virology, 1995, 210: 100-108; Rem ond, M. et al., J Gen Virol, 1996, 77: 37-48).