A bacteriophage containing RNA.

TLDR: According to the suggested very close relationship between protein synthesis and RNA synthesis, it would then explain how an amino acid analog may interfere directly with the synthesis of a specific viral RNA, having shown it unlikely that new enzymes are necessary for the production of WEE RNA in infected cells.

Abstract: rapid exchangeability of apparently incorporated FPA could therefore mean that the proteins containing FPA instead of PA are readily turned over after PA is added; or it could mean that FPA was never really incorporated in the manner of a normal amino acid. Some later experiments have suggested that the latter is the case. This provides a likely explanation for the competitive inhibition of amino acid incorporation produced by FPA; that is, the inhibition of protein synthesis. According to the suggested very close relationship between protein synthesis and RNA synthesis, it would then explain how an amino acid analog may interfere directly with the synthesis of a specific viral RNA, having shown it unlikely that new enzymes are necessary for the production of WEE RNA in infected cells. Such a direct mode of action of FPA seems in fact to be indicated by our experiments.