Sequence analysis of bovine adenovirus type 2 early region 1 and pIX gene

Bovine adenoviruses (BAVs) cause both respiratory and/or enteral diseases in cattle and are widespread throughout the world. We have sequenced the extreme left end (0 to 12.2 mu) of the BAV2 genome. Partial analysis of the nucleotide sequence revealed 12 potential open reading frames (ORFs) which could encode for polypeptides of 50 or more amino acids. These ORFs were compared to those of the early region 1 (E1) proteins and hexon-associated protein IX (pIX) from other adenoviruses (Ads). The 4 major ORFs show homology to known Ad polypeptides. The 4 BAV2 ORFs are located in approximately the same area as that of the human Ad type 5 (HAd5) E1A, E1B and pIX ORFs. ORF1 has the potential to encode a 119-amino-acid-long polypeptide that is 85.7% homologous (over 42 amino acids) to the E1A conserved region III of both HAd2 and HAd5. ORF2 and ORF3 have the potential to code for 160- and 408-amino-acid-long polypeptides, respectively. The 160-amino-acid-long polypeptide exhibits 71.3% homology to the small T antigen of HAd40, and the 408-amino-acid polypeptide exhibits 67.0% homology with the large T antigen of HAd2. Both the small T antigen of HAd40 and the large T antigen of HAd2 are translated from the E1B mRNAs. ORF4 has the potential to code for a 117-amino-acid-long polypeptide that has 77.9% homology with the Tupaia adenovirus pIX.