The Structural Proteins of Chick Embryo Lethal Orphan Virus (Fowl Adenovirus Type 1)

Chick embryo lethal orphan (CELO) virus (fowl adenovirus type 1) contains at least 14 structural proteins with polypeptide molecular weights ranging from 100K to about 6K. A nomenclature of the CELO virion polypeptides is presented and the molar proportion of each polypeptide has been estimated. The CELO virus pentons were specifically released from the virion by dialysis against borate-based calcium-magnesium saline. The penton base (polypeptide III, mol. wt. 92K) and two fibres were separated, characterized and their polypeptides were correlated with their morphological positions in the virion. Peptide mapping suggested that the long fibre (polypeptide IV, mol. wt. 65K), and the short fibre (polypeptide VII, mol. wt. 44.5K) were not related in their primary sequences and are therefore probably encoded by separate genes. The time course of synthesis of the CELO virion polypeptides indicated that, like their mammalian adenovirus counterparts, they are synthesized late (after viral DNA replication).