Expression of protein IIIa of human adenovirus type 2 in Escherichia coli

We have constructed a plasmid encoding the protein IIIa gene of human adenovirus type 2. The gene was expressed under the control of the hybrid tac (trp-lac) promoter; the protein was synthesized at levels up to 5% of newly synthesized protein after IPTG induction. The protein IIIa produced in Escherichia coli has an apparent Mr on sodium dodecyl sulfate-polyacrylamide gels of 67 kDa, and was revealed with anti-adenovirus serum in Western blotting. The protein IIIa produced in bacteria was phosphorylated in the presence of [gamma-32P]ATP.