S gene product: identification and membrane localization of a lysis control protein

Abstract

The product of the phage S gene was previously shown to be reqired for an essential step in triggering host cell [Escherichia coli] lysis. By using 2 different protein labeling systems, maxicells and UV-irradiated infected cells, are identified the S gene product as an 8500 MW polypeptide associated with the cell envelope. The apparent MW is significantly < 11,500 predicted from the S gene sequence. One could not confirm 2 previous identifications of S gene products, an acidic 15,000-MW polypeptide found by 2-dimensional gel electrophoresis of infected cells and a 5500-MW polypeptide in purified phage particles.