A biochemical assay for the transcription-antitermination function of the coliphage λ N gene product

Abstract An in vitro assay has been developed for the antiterminating activity of the N gene product (p N ) of bacterio-phage λ, based on the N -dependent stimulation of trp mRNA synthesis from the DNA templates of λ trp transducing phages. Using this assay system, we show (a) that the stimulation of trp mRNA synthesis by p N requires the cis -dominant nut L site on the λ chromosome and (b) that p N can participate in vitro in the formation of functional antiterminating transcription complexes.