Genetic organization and sequence analysis of pVIII, fiber and early region 4 of bovine adenovirus type 7.

The DNA sequence of 8,810 nucleotides at the right end of bovine adenovirus type 7 (BAV7) genome was determined and compared with similar regions of other adenoviruses. This genomic region of BAV7 consists of sequences encoding partial 33K, pVIII, fiber, putative early region 4 (E4) proteins and other unassigned proteins. However, BAV7 E3 region is not present in the expected location between pVIII and fiber as BAV7 intergenic region between pVIII and fiber genes is only 183 nucleotides. The predicted pVIII and fiber demonstrates highest homology to corresponding proteins of ovine adenovirus 287 (OAV287), bovine adenovirus-4 (BAV4) and egg drop syndrome virus (EDSV). The E4 region encodes three ORFs, which shows significant homology only to corresponding proteins encoded by E4 region of OAV287 and BAV4. Sequence comparisons, phylogenetic analysis and overall genome organization in this region of BAV7 provide further evidence for the inclusion of BAV7 together with OAV287, BAV4, and EDSV in the proposed genus 'Atadenovirus'.