Components of multiprotein-RNA complex that controls transcription elongation in Escherichia coli phage lambda

This chapter discusses the components of multiprotein-RNA complex that controls transcription elongation in Escherichia Coli phage λ. Studies of bacteriophage A led to the discovery of several basic mechanisms of transcriptional regulation. One of these is transcriptional antitermination, the process in which genes whose transcription is otherwise blocked by premature termination are expressed through termination suppression. In λ and related phages, genome-specific antiterminators convert RNA polymerase (RNAP) into a termination-resistant form during early phases of transcription elongation. The chapter describes the current understanding of how one such antiterminator, the λ N gene product, works. The chapter reviews the methods of overproduction, isolation, and assay of the N protein as well as several accessory factors that modulate transcription elongation in Escherichia coli in the form of a multiprotein-RNA complex. The availability of N and Nus factors in large scale should now make it possible not only to attempt to determine the structures of the individual protein components, and the various RNA-protein and protein-protein complexes by biophysical methods, but also to examine these interactions by conventional biochemical methods.