MODIFIED DNA-DEPENDENT RNA POLYMERASE FROM E COLI INFECTED WITH BACTERIOPHAGE T4

It has been shown by Buchanan and Sköld (1964) that the DNA-dependent RNA polymerase activity in crude extracts from E.coli measured using DNA from T4-phage as template shows a strong decrease within a few minutes after T4-phage infection. Protein synthesis is required for this inactivation. The authors, and later Furth and Pizer (1966), ascribed this phenomenon to the appearance of an inhibitor. It has been demonstrated by Hall (1967) that this inactivation appears much less pronounced when calf thymus DNA is used as the template. In this case activity even increases again at later times. It will be shown in this communication that these effects may be attributed to a structural modification of E.coli polymerase as a consequence of phage infection (G. Walter, W. Seifert, W. Zillig, 1967). © 1968.