NusA is a key component in both Prevention and enhancement of transcriptional termination. It is important in both Rho-dependent and intrinsic termination, as well as in lambda and other phage antitermination systems. The gene was first identified by isolation of the nusAl mutation, which restricts bacteriophage l growth by preventing the antitermination activity of the l N protein. NusA is involved in transcriptional antitermination in the cell. It has been shown to specifically aid in read-through of the RNA polymerase genes rpoB and rpoC, as well as in successful synthesis of the ribosomal RNA genes. Recombinant NusA was expressed in E. coli and purified by using conventional chromatography techniques. Alternative Names: ECK3158 protein, Transcription termination/antitermination L factor, JW3158 protein, NusA protein, Transcription termination/antitermination L factor protein