Strategy of the viral genome / edited by G.E.W. Wolstenholme and Maeve O'Connor.

  • Symposium on Strategy of the Viral Genome (1971 : London, England)
Date:
1971
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Strategy of the viral genome / edited by G.E.W. Wolstenholme and Maeve O'Connor. Source: Wellcome Collection.

    24/432 (page 10)
    IO SEYMOUR S. COHEN SYNTHESIS OF VIRUS-INDUCED ENZYMES IN VITRO As Fig. 3 shows, in addition to the synthesis in T-even phage systems ofoneormore groups of early enzymes which catalyse reactions essential for DNA synthesis, there is a later synthesis of other proteins, many of which are involved in phage structure and assembly (Cohen 1968). Some of these events have recently been produced in cell-free systems. At the same time our knowledge of the mechanisms of protein synthesis has advanced— knowledge which has been both derived from phage systems and used to explore these systems. For example, the study of transcription on T4 DNA i-- MATURE VIRUS ^ POLYPEPTIDES LYSOZYME, POLYPEPTIDE PRECURSOR, ^ AND VIRUS COMPONENTS DNA dTMP SYNTHETASE dCMP HYDROXYMETHYLASE -] EARLY EARLY PROTEINS? INTERNAL ANTIGEN (гП PRODUCT?) 5 10 15 20 25 Minutes Fig. 3. The timing and sequence of early proteins, DNA and late proteins in T-even r+ phage infection of E. coli strain В in a glucose- mineral medium at 37°C (Cohen 1968). led to the detection of sigma factors in normal and phage-infected cells (Walter, Seifert and Zillig 1968; Bautz, Bautz and Dunn 1969; Travers and Burgess 1969) and has in turn led to questions about the role of such factors in the control of the different times of appearance of the virus- induced proteins. Study of the structure of tRNA led Sueoka and Kano- Sueoka (1964) and Hsu, Foft and Weiss (1967) to detect new species of tRNA in T4 and T5 infection. The role of these new tRNA species in the control of virus multiplication is far from clear. A sharp change in the composition of ribosomes after infection was shown in an isolated system. This change may help to explain the arrest of synthesis of host proteins