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<table><tr><td colspan='2'>[[6c6s]] is a 9 chain structure with sequence from [http://en.wikipedia.org/wiki/Ecoli Ecoli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6C6S OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6C6S FirstGlance]. <br>
<table><tr><td colspan='2'>[[6c6s]] is a 9 chain structure with sequence from [http://en.wikipedia.org/wiki/Ecoli Ecoli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6C6S OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6C6S FirstGlance]. <br>
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==See Also==
==See Also==
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*[[RNA polymerase|RNA polymerase]]
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*[[RNA polymerase 3D structures|RNA polymerase 3D structures]]
== References ==
== References ==
<references/>
<references/>
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__TOC__
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</StructureSection>
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</SX>
[[Category: DNA-directed RNA polymerase]]
[[Category: DNA-directed RNA polymerase]]
[[Category: Ecoli]]
[[Category: Ecoli]]
Revision as of 20:38, 6 March 2020
CryoEM structure of E.coli RNA polymerase elongation complex bound with RfaH
6c6s is a 9 chain structure with sequence from Ecoli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
[RPOC_ECOLI] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.[HAMAP-Rule:MF_01322] [RPOZ_ECOLI] 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.[HAMAP-Rule:MF_00366] [RFAH_ECOLI] Enhances distal genes transcription elongation in a specialized subset of operons that encode extracytoplasmic components. RfaH is recruited into a multi-component RNA polymerase complex by the ops element, which is a short conserved DNA sequence located downstream of the main promoter of these operons. Once bound, RfaH suppresses pausing and inhibits Rho-dependent and intrinsic termination at a subset of sites. Termination signals are bypassed, which allows complete synthesis of long RNA chains. Enhances expression of several operons involved in synthesis of lipopolysaccharides, exopolysaccharides, hemolysin, and sex factor. Also negatively controls expression and surface presentation of AG43 and possibly another AG43-independent factor that mediates cell-cell interactions and biofilm formation.[1][2][3][4][5][6][7][8][9] [RPOA_ECOLI] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. This subunit plays an important role in subunit assembly since its dimerization is the first step in the sequential assembly of subunits to form the holoenzyme.[HAMAP-Rule:MF_00059] [RPOB_ECOLI] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.[HAMAP-Rule:MF_01321]
Publication Abstract from PubMed
NusG/RfaH/Spt5 transcription elongation factors are the only transcription regulators conserved across all life. Bacterial NusG regulates RNA polymerase (RNAP) elongation complexes (ECs) across most genes, enhancing elongation by suppressing RNAP backtracking and coordinating rho-dependent termination and translation. The NusG paralog RfaH engages the EC only at operon polarity suppressor (ops) sites and suppresses both backtrack and hairpin-stabilized pausing. We used single-particle cryoelectron microscopy (cryo-EM) to determine structures of ECs at ops with NusG or RfaH. Both factors chaperone base-pairing of the upstream duplex DNA to suppress backtracking, explaining stimulation of elongation genome-wide. The RfaH-opsEC structure reveals how RfaH confers operon specificity through specific recognition of an ops hairpin in the single-stranded nontemplate DNA and tighter binding to the EC to exclude NusG. Tight EC binding by RfaH sterically blocks the swiveled RNAP conformation necessary for hairpin-stabilized pausing. The universal conservation of NusG/RfaH/Spt5 suggests that the molecular mechanisms uncovered here are widespread.
Structural Basis for Transcript Elongation Control by NusG Family Universal Regulators.,Kang JY, Mooney RA, Nedialkov Y, Saba J, Mishanina TV, Artsimovitch I, Landick R, Darst SA Cell. 2018 Jun 14;173(7):1650-1662.e14. doi: 10.1016/j.cell.2018.05.017. Epub, 2018 Jun 7. PMID:29887376[10]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Bailey MJ, Koronakis V, Schmoll T, Hughes C. Escherichia coli HlyT protein, a transcriptional activator of haemolysin synthesis and secretion, is encoded by the rfaH (sfrB) locus required for expression of sex factor and lipopolysaccharide genes. Mol Microbiol. 1992 Apr;6(8):1003-12. PMID:1584020
↑ Bailey MJ, Hughes C, Koronakis V. Increased distal gene transcription by the elongation factor RfaH, a specialized homologue of NusG. Mol Microbiol. 1996 Nov;22(4):729-37. PMID:8951819
↑ Leeds JA, Welch RA. Enhancing transcription through the Escherichia coli hemolysin operon, hlyCABD: RfaH and upstream JUMPStart DNA sequences function together via a postinitiation mechanism. J Bacteriol. 1997 Jun;179(11):3519-27. PMID:9171395
↑ Bailey MJ, Hughes C, Koronakis V. RfaH and the ops element, components of a novel system controlling bacterial transcription elongation. Mol Microbiol. 1997 Dec;26(5):845-51. PMID:9426123
↑ Bailey MJ, Hughes C, Koronakis V. In vitro recruitment of the RfaH regulatory protein into a specialised transcription complex, directed by the nucleic acid ops element. Mol Gen Genet. 2000 Jan;262(6):1052-9. PMID:10660066
↑ Artsimovitch I, Landick R. The transcriptional regulator RfaH stimulates RNA chain synthesis after recruitment to elongation complexes by the exposed nontemplate DNA strand. Cell. 2002 Apr 19;109(2):193-203. PMID:12007406
↑ Santangelo TJ, Roberts JW. RfaH, a bacterial transcription antiterminator. Mol Cell. 2002 Apr;9(4):698-700. PMID:11983161
↑ Kang JY, Mooney RA, Nedialkov Y, Saba J, Mishanina TV, Artsimovitch I, Landick R, Darst SA. Structural Basis for Transcript Elongation Control by NusG Family Universal Regulators. Cell. 2018 Jun 14;173(7):1650-1662.e14. doi: 10.1016/j.cell.2018.05.017. Epub, 2018 Jun 7. PMID:29887376 doi:http://dx.doi.org/10.1016/j.cell.2018.05.017
