to determine which amino acids are phosphorylated and whether phosphorylation in vitro occurs at the same amino acid sites that are phosphorylated in vivo , the ad12 e1a t-antigen species synthesized by infected cells were metabolically labeled with 32pi and compared with the e. coli-produced e1a t antigens labeled in vitro with [ gamma-32p ] atp by using the partially purified kinase .
C0031715
phosphorylation
C0031727
kinase