Morphological localization of the bacteriophage tail enzyme.

In an earlier report dealing with the chemistry of viral invasion, Barrington and Kozloff (1,2) showed that incubat,ion of various T series bacteriophages with N16-labeled Escherichiu coli B cell walls caused the release of as much as 15 per cent of the total nitrogen from the host cell walls. The characteristics of this interaction appeared to be similar to those of an enzymatic reaction, and it waa suggested that the active site was on the virus tail. This paper is also concerned with the nature of this reaction and with the morphological location of the proposed enzyme. A simple assay system for the lytic activity of phage on cell walls has been devised, by using E. coti cell walls prepared from bacteria labeled with C!“. The experiments in this paper show that phages Tz and T4, altered by various chemical or physical treatments, have enzymatic activity on cell walls. Evidence will be presented which indicates that the intact phage is enzymatically inactive and that a phage particle has activity only after the tail haa been shortened.