Characterization of human adenovirus type 5 early region 1A polypeptides using antitumor sera and an antiserum specific for the carboxy terminus

The adenovirus 5 early region 1A (ElA: 0–4.5 map units) proteins synthesized early after infection of KB cells without pretreatment of the cells with metabolic inhibitors have been studied. The E1A mRNA species of 1.1 and 0.9 kilobases (Kb) are processed from alternative 5′ splice sites to a common 3′ splice site of the same initial transcript and code for proteins of 289 and 243 amino acids in length that share common amino and carboxy …