Genetic analysis of the N transcription antitermination system of phage lambda.

Regulation of coliphage lambda gene expression occurs, in part, by a process of termination and antitermination of transcription. The N gene product, one of two lambda encoded antitermination proteins, acts with host encoded proteins, Nus, at sites, nut, located downstream of the early promoters to render the transcribing RNA polymerase resistant to many downstream termination signals. We discuss the nature of some of the proteins and sites involved in this process.