Host specificity of DNA produced by Escherichia coli: V. The role of methionine in the production of host specificity

Abstract

Bacteriophage λ grown in auxotrophic met−, pro− or arg− strainsf of Escherichia coli K12 in the presence of the required amino acids show an efficiency of plating of approximately 1 on E. coli strains K12 and C. However, if met− cells are deprived of methionine during a portion of the latent period, the efficiency of plating of the progeny phage is lower on the host K12 than on strain C. Similar results are obtained with met− auxotrophs of strains B and K12(P1); deprivation of methionine during the latent period results in the production of phage with lower efficiency of plating on the host strain than on strain C. Such an effect is not observed following a similar starvation for proline or arginine. These results suggest that methionine is specifically required for the production of host specificity of DNA.