Gene D of bacteriophage phi X 174: absence of transcriptional and translational regulatory properties.

The only evidence that a gene product of phi chi 174 is involved in the regulation of phage transcription was presented by Clements and Sinsheimer (1974) for gene D. I. found, in attempting to investigate this possibility further, that the D protein had no regulatory effect. When the D protein was eliminated by various nonsense mutations, all other phage proteins were synthesized at rates nearly identical to the wild-type control. There was also no significant difference in the amount of phage-specific RNA synthesis as a proportion of the total RNA synthesis when the D mutants were compared with wild type. No evidence was detected for a polar effect of gene D nonsense mutants on the expression of genes F, G, and H. The relative molar rates of synthesis of D, F, G, and H, synthesized during a normal infection were 29, 4.9, 3.3, and 1.0, respectively, with an accuracy of +/- 20%.