Role of Escherichia coli RNA polymerase alpha subunit in modulation of pausing, termination and anti-termination by the transcription elongation factor NusA.

摘要: The alpha subunit (alpha) of RNA polymerase (RNAP) is critical for assembly and positive control transcription initiation in Escherichia coli. Here, we report that also plays a role elongation, this involves direct interaction between NusA factor. During vitro without NusA, interacts with the nascent RNA, as revealed by photocrosslinking. When present, crosslinks to rather than alpha. We show NusA-RNA diminished during an RNAP mutant lacks C-terminus beyond amino acid 235, including so-called CTD. absence CTD affects NusA's ability enhance pausing, termination at intrinsic terminators anti-termination phage lambda Q anti-terminator, but not N anti-terminator. functions are recovered even when done excess condition which does restore crosslinking. By affinity chromatography, directly alpha, beta beta', Hence, alpha-NusA vital transcript elongation termination.