2k06
From Proteopedia
Solution structure of the aminoterminal domain of E. coli NusG
Structural highlights
Function[NUSG_ECOLI] 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 and phage lambda N-mediated transcriptional antitermination.[1] [2] [3] [4] [5] [6] [7] [8] [9] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedNusG is a conserved regulatory protein that interacts with elongation complexes (ECs) of RNA polymerase, DNA, and RNA to modulate transcription in multiple and sometimes opposite ways. In Escherichia coli, NusG suppresses pausing and increases elongation rate, enhances termination by E. coli rho and phage HK022 Nun protein, and promotes antitermination by lambdaN and in ribosomal RNA operons. We report NMR studies that suggest that E. coli NusG consists of two largely independent N- and C-terminal structural domains, NTD and CTD, respectively. Based on tests of the functions of the NTD and CTD and variants of NusG in vivo and in vitro, we find that NTD alone is sufficient to suppress pausing and enhance transcript elongation in vitro. However, neither domain alone can enhance rho-dependent termination or support antitermination, indicating that interactions of both domains with ECs are required for these processes. We propose that the two domains of NusG mediate distinct interactions with ECs: the NTD interacts with RNA polymerase and the CTD interacts with rho and other regulators, providing NusG with different combinations of interactions to effect different regulatory outcomes. Two structurally independent domains of E. coli NusG create regulatory plasticity via distinct interactions with RNA polymerase and regulators.,Mooney RA, Schweimer K, Rosch P, Gottesman M, Landick R J Mol Biol. 2009 Aug 14;391(2):341-58. Epub 2009 Jun 3. PMID:19500594[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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