The Activity of Salmonella phage P22 gene 24 product in Escherichia coli

Abstract

Induction of Escherichia coli lysogenic for prophage λ imm22 (carrying the Salmonella phage P22 early regulator, gene 24) results in gene 24-dependent prophage-controlled expression of the galactose operon. Comparing gal escape synthesis by γ λ imm2l, and λ imm22 prophages, we find that 24 product, like the N products of coliphages λ and 21, acts as an antiterminator and polarity suppressor for transcription originating at the P l promoter, exhibits specificity for its own genome, and requires nusA + product for activity. The apparent contradiction between these observations and previously published data is discussed.