BACTERIOPHAGE-N4-INDUCED TRANSCRIBING ACTIVITIES IN ESCHERICHIA-COLI .2. ASSOCIATION OF THE N4 TRANSCRIPTIONAL APPARATUS WITH THE CYTOPLASMIC MEMBRANE

Several lines of evidence indicate that the 2 rifampicin-resistant transcribing activities induced by E. coli phage N4 are associated with the cell membrane. First, under lysis conditions designed to avoid nonspecific DNA-membrane association, the N4 RNA-synthesizing activities (and the endogenous N4 DNA) cosediment with the E. coli DNA membrane complex in sucrose gradients. Second, it was not possible to dissociate the activities from the DNA-membrane complex by any treatment which was tested; e.g., after high salt treatments (up to 4 M NaCl), which do not irreversibly inactivate the activities, the activities remain stably associated with the complex. Low detergent concentrations inhibit the activities and irreversible inactivation results from treatment with the anionic detergent, sodium deoxycholate. Third, upon separation of the cell envelope of N4-infected E. coli into inner (cytoplasmic) and outer membrane fractions, the N4-induced RNA-synthesizing activity is found associated with the cytoplasmic membrane. Based on electrophoretic migration in sodium dodecyl sulfate-polyacrylamide gels, the N4-induced polypeptides found associated with the DNA-membrane complex are also found selectively associated with the cytoplasmic membrane.