N protein from lambdoid phages transforms NusA into an antiterminator by modulating NusA-RNA polymerase flap domain interactions

摘要: Interaction of the lambdoid phage N protein with bacterial transcription elongation factor NusA is key component in process antitermination. A convex surface E. coli NusA-NTD, located opposite to its RNA polymerase-binding domain (the β-flap domain), directly interacts antitermination complex. We hypothesized that this N-NusA interaction induces allosteric effects on NusA-RNAP leading transformation into a facilitator process. Here we showed mutations specifically defective for exhibited altered NusA-nascent and have widened exit channel indicating an intricate role flap The presence reoriented RNAP binding which changed pattern domain. These changes caused significant spatial rearrangement as well β' dock domains form more constricted N-modified complex (EC), might play converting propose addition affecting active center EC, also mechanistic