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Structure of THE RNA POLYMERASE LAMBDA-BASED ANTITERMINATION COMPLEXStructure of THE RNA POLYMERASE LAMBDA-BASED ANTITERMINATION COMPLEX
Structural highlights
Function[RPOA_ECO57] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. [RS10_ECO57] Involved in the binding of tRNA to the ribosomes. [RPOZ_ECO57] Promotes RNA polymerase assembly. Latches the N- and C-terminal regions of the beta' subunit thereby facilitating its interaction with the beta and alpha subunits (By similarity). [RPOC_ECO57] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. [NUSB_ECO57] Involved in transcription antitermination. Required for transcription of ribosomal RNA (rRNA) genes. Binds specifically to the boxA antiterminator sequence of the ribosomal RNA (rrn) operons.[HAMAP-Rule:MF_00073] [RPOB_ECO57] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. [NUSA_ECO57] Participates in both transcription termination and antitermination. [NUSG_ECO57] Participates in transcription elongation, termination and antitermination. In the absence of Rho, increases the rate of transcription elongation by the RNA polymerase (RNAP), probably by partially suppressing pausing. In the presence of Rho, modulates most Rho-dependent termination events by interacting with the RNAP to render the complex more susceptible to the termination activity of Rho. May be required to overcome a kinetic limitation of Rho to function at certain terminators. Also involved in ribosomal RNA transcriptional antitermination.[HAMAP-Rule:MF_00948] [REGN_LAMBD] Antitermination proteins positively regulate expression of the phage early and late gene operons. Bacterial host RNA polymerase modified by these antitermination proteins transcribes through termination sites that otherwise prevent expression of the regulated genes. N protein regulates the transition from the early to the middle stage of lytic development. It is a transcription antitermination protein that prevents termination at the rho-dependent tL and tR transcription termination sites. Publication Abstract from PubMedBacteriophage lambdaN protein, a model anti-termination factor, binds nascent RNA and host Nus factors, rendering RNA polymerase resistant to all pause and termination signals. A 3.7-A-resolution cryo-electron microscopy structure and structure-informed functional analyses reveal a multi-pronged strategy by which the intrinsically unstructured lambdaN directly modifies RNA polymerase interactions with the nucleic acids and subverts essential functions of NusA, NusE, and NusG to reprogram the transcriptional apparatus. lambdaN repositions NusA and remodels the beta subunit flap tip, which likely precludes folding of pause or termination RNA hairpins in the exit tunnel and disrupts termination-supporting interactions of the alpha subunit C-terminal domains. lambdaN invades and traverses the RNA polymerase hybrid cavity, likely stabilizing the hybrid and impeding pause- or termination-related conformational changes of polymerase. lambdaN also lines upstream DNA, seemingly reinforcing anti-backtracking and anti-swiveling by NusG. Moreover, lambdaN-repositioned NusA and NusE sequester the NusG C-terminal domain, counteracting rho-dependent termination. Other anti-terminators likely utilize similar mechanisms to enable processive transcription. Structural Basis for the Action of an All-Purpose Transcription Anti-termination Factor.,Krupp F, Said N, Huang YH, Loll B, Burger J, Mielke T, Spahn CMT, Wahl MC Mol Cell. 2019 Feb 12. pii: S1097-2765(19)30036-X. doi:, 10.1016/j.molcel.2019.01.016. PMID:30795892[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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