Effect of bacteriophage lambda infection on synthesis of groE protein and other Escherichia coli proteins

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Abstract
Two-dimensional gel electrophoresis was used to quantitate the changes in rates of synthesis that follow phage .lambda. infection for 21 E. coli proteins, including groE and dnaK proteins. Although total protein synthesis and the rates of synthesis of most individual E. coli proteins decreased after infection, some proteins, including groE protein, dnaK protein and stringent starvation protein, showed increases to rates substantially above their preinfection rates. Infection by .lambda. O- affected host synthesis in the same way as infection by .lambda.+, whereas infection by .lambda. N- showed no detectable effect on host synthesis. Deletion of the early genes between att and N abolished the effect, and shorter deletions in this region gave intermediate effects. By this sort of deletion mapping, it was shown that a large part, though not all, of the effect of .lambda. infection on host protein synthesis can be ascribed to the early region that contains phage genes Ea10 and ral. The changes in protein synthesis after infection were compared with the changes that occur in uninfected cells on heat shock or amino acid starvation. The spectrum of changes that occurred on infection was very different from that seen after heat shock but quite similar to that seen during amino acid starvation. Despite this similarity of the effects of .lambda. infection and starvation, an increase in the level of guanosine tetraphosphate was not seen during infection. The groE protein was the same protein as B56.5 of Lemaux et al. (1978) and A protein of Subramanian et al. (1976).