Synthesis of Virus‐Specific Proteins in <i>Escherichia coli</i> Infected with the RNA Bacteriophage MS2¹

Abstract

The synthesis of virus‐specific proteins following infection of Escherichia coli with the RNA phage MS2 was studied using spheroplasts exposed to low concentrations of actinomycin D in the presence of an amino acid mixture containing radioactive leucine or histidine. Under the conditions employed there was about 75% inhibition of virus production and 99% inhibition of host protein synthesis by actinomycin. Fractionation of the phage‐induced prcteins by acrylamide gel electrophoresis revealed the presence of three major peaks, I, II, and III. The largest one (peak III) was characterized as coat protein. The rate of synthesis of proteins I and II declines before that of the coat protein has reached its maximum.