Unique Genome Arrangement of an Ovine Adenovirus: Identification of New Proteins and Proteinase Cleavage Sites

Abstract

The completed sequence and genome organization of OAV287, a serologically distinct ovine adenovirus, is described. The genome of 29,544 bp has inverted terminal repeats that are only 46 bp in length. Many OAV genes are identified by their homology with other adenovirus (Ad) sequences but three groups of reading frames show little homology. One group at the left-hand end of the genome probably represents the E1A/E1B regions. Two others, on the complementary strand at the right-hand end of the genome, are tentatively proposed as the E4 and E3 regions. They are separated by approximately 1 kb of A/T-rich sequence of unknown function with E3 being adjacent to the terminus. Structural proteins V and IX of human Ads are absent from the OAV genome but a new, processed, 28-kDa virion polypeptide is encoded on the strand complementary to the proposed E1A region. The coding sequences for two other structural proteins are unidentified. The OAV penton protein lacks the region containing an Arg/Gly/Asp sequence that, in human adenoviruses, is thought to interact with cellular integrins to facilitate virus entry. Analysis of proteins and peptides in purified OAV identified several cleavage sites utilized by the Ad proteinase. Some of these were previously identified in human Ad proteins, but new sites, some of which did not conform to the known specificity of the human Ad proteinase, were also identified. The data emphasize that this ovine virus differs significantly from other known human and animal adenoviruses.

Molecular Characterization of a Lizard Adenovirus Reveals the First Atadenovirus with Two Fiber Genes and the First Adenovirus with Either One Short or Three Long Fibers per Penton

“…This anomalous electrophoretic mobility may indicate posttranslational modifications in LAdV-2 fiber1. Protein p32K is considerably larger in reptilian AdVs than its homologue in the prototype atadenovirus ovine adenovirus 7 (OAdV-7) (32 kDa) (9) and is highly basic (pI 11) (Table 1), suggesting its ability to bind to the viral genome and play a role similar to that of mastadenovirus-specific polypeptide V (16). We interpret an ϳ30-kDa band as the precursor of polypeptide VIII (pVIII), probably coming from the immature particles present in the purification.…”

“…They were noted for the strikingly high AϩT content of their DNA, hence the genus name (6)(7)(8). The genome of the first fully sequenced reptilian AdV (snake adenovirus 1 [SnAdV-1]) showed a characteristic atadenoviral gene arrangement (9), albeit with an equilibrated GϩC con-tent (5,10). The analysis of short sequences from the DNA-dependent DNA polymerase (pol) gene of further, newly reported AdVs from a number of additional animals in the order Squamata, confirmed the balanced GϩC content and the phylogenetic place in the Atadenovirus genus for all of these snake and lizard viruses (11)(12)(13).…”

Biology of Ovine Adenovirus Infection of Nonpermissive Cells

“…OAdV is distinguished from members of the mast-and aviadenoviruses by a different genome organization and by the fact that many open reading frames show no detectable homology to those of any other adenoviruses (53)(54)(55)(56). Because the biology of OAdV is not well understood, the outcome of infecting nonovine, particularly human, cells with OAdV is of interest.…”

E4 gene function in adenovirus, adenovirus vector and adeno-associated virus infections.

“…Non-human mammalian Ads have E4 regions with homology to Ad5 E4 which varies in extent from considerable identity across four reading frames in bovine Ad2 (Fitzgerald et al, 1997) to limited homology only with Orf6 in Author for correspondence : Keith N. Leppard. Fax j44 1203 523701. e-mail Keith. Leppard!warwick.ac.uk murine Ad1 (Ball et al, 1991) and ovine Ad (Vrati et al, 1996) ; there may be two Orf6 homologues in the ovine virus.…”