DNA-dependent RNA-directed protein synthesis in vitro. IV. Peptide analysis of an in vitro and in vivo phi X174 structural protein.

An antibody-precipitable structural protein from the bacteriophage varphiX174 was purified from an in vitro protein-synthesizing system primed with the replicative DNA of the virus. This protein was trypsin digested in the presence of the differentially labeled analogous protein that was purified from the bacteriophage. The tryptic hydrolysate was subjected to high resolution peptide chromatography which revealed essentially identical patterns for the varphiX174 proteins synthesized in vitro and in vivo.