3ihq: Difference between revisions
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[[Image: | ==Crystal Structure of Reduced C10S Spx in Complex with the Alpha C-terminal Domain of RNA Polymeras== | ||
<StructureSection load='3ihq' size='340' side='right' caption='[[3ihq]], [[Resolution|resolution]] 1.90Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3ihq]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3IHQ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3IHQ FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=IMD:IMIDAZOLE'>IMD</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1z3e|1z3e]]</td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">BSU11500, spxA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1423 Bacillus subtilis]), BSU01430, rpoA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1423 Bacillus subtilis])</td></tr> | |||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/DNA-directed_RNA_polymerase DNA-directed RNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.6 2.7.7.6] </span></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3ihq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ihq OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3ihq RCSB], [http://www.ebi.ac.uk/pdbsum/3ihq PDBsum]</span></td></tr> | |||
</table> | |||
== Function == | |||
[[http://www.uniprot.org/uniprot/SPX_BACSU SPX_BACSU]] Interferes with activator-stimulated transcription by interaction with the RNA polymerase alpha-CTD. May function to globally reduce transcription of genes involved in growth- and development-promoting processes and to increase transcription of genes involved in thiol homeostasis, during periods of extreme stress. Negatively affects competence and sporulation. Its degradation by the MecA/ClpXP complex is needed for competence development.<ref>PMID:11703662</ref> <ref>PMID:12642660</ref> [[http://www.uniprot.org/uniprot/RPOA_BACSU RPOA_BACSU]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ih/3ihq_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
BACKGROUND: Spx, an ArsC (arsenate reductase) family member, is a global transcriptional regulator of the microbial stress response and is highly conserved amongst Gram-positive bacteria. Bacillus subtilis Spx protein exerts positive and negative control of transcription through its interaction with the C-terminal domain of the RNA polymerase (RNAP) alpha subunit (alphaCTD). Spx activates trxA (thioredoxin) and trxB (thioredoxin reductase) in response to thiol stress, and bears an N-terminal C10XXC13 redox disulfide center that is oxidized in active Spx. METHODOLOGY/PRINCIPAL FINDINGS: The structure of mutant Spx(C10S) showed a change in the conformation of helix alpha4. Amino acid substitutions R60E and K62E within and adjacent to helix alpha4 conferred defects in Spx-activated transcription but not Spx-dependent repression. Electrophoretic mobility-shift assays showed alphaCTD interaction with trxB promoter DNA, but addition of Spx generated a supershifted complex that was disrupted in the presence of reductant (DTT). Interaction of alphaCTD/Spx complex with promoter DNA required the cis-acting elements -45AGCA-42 and -34AGCG-31 of the trxB promoter. The Spx(G52R) mutant, defective in alphaCTD binding, did not interact with the alphaCTD-trxB complex. Spx(R60E) not only failed to complex with alphaCTD-trxB, but also disrupted alphaCTD-trxB DNA interaction. CONCLUSIONS/SIGNIFICANCE: The results show that Spx and alphaCTD form a complex that recognizes the promoter DNA of an Spx-controlled gene. A conformational change during oxidation of Spx to the disulfide form likely alters the structure of Spx alpha helix alpha4, which contains residues that function in transcriptional activation and alphaCTD/Spx-promoter interaction. The results suggest that one of these residues, R60 of the alpha4 region of oxidized Spx, functions in alphaCTD/Spx-promoter contact but not in alphaCTD interaction. | |||
Promoter recognition by a complex of Spx and the C-terminal domain of the RNA polymerase alpha subunit.,Nakano MM, Lin A, Zuber CS, Newberry KJ, Brennan RG, Zuber P PLoS One. 2010 Jan 13;5(1):e8664. PMID:20084284<ref>PMID:20084284</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[RNA polymerase|RNA polymerase]] | *[[RNA polymerase|RNA polymerase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Bacillus subtilis]] | [[Category: Bacillus subtilis]] | ||
[[Category: DNA-directed RNA polymerase]] | [[Category: DNA-directed RNA polymerase]] | ||
[[Category: Brennan, R G | [[Category: Brennan, R G]] | ||
[[Category: Newberry, K J | [[Category: Newberry, K J]] | ||
[[Category: Disulfide bond]] | [[Category: Disulfide bond]] | ||
[[Category: Dna-directed rna polymerase]] | [[Category: Dna-directed rna polymerase]] |
Revision as of 22:49, 25 December 2014
Crystal Structure of Reduced C10S Spx in Complex with the Alpha C-terminal Domain of RNA PolymerasCrystal Structure of Reduced C10S Spx in Complex with the Alpha C-terminal Domain of RNA Polymeras
Structural highlights
Function[SPX_BACSU] Interferes with activator-stimulated transcription by interaction with the RNA polymerase alpha-CTD. May function to globally reduce transcription of genes involved in growth- and development-promoting processes and to increase transcription of genes involved in thiol homeostasis, during periods of extreme stress. Negatively affects competence and sporulation. Its degradation by the MecA/ClpXP complex is needed for competence development.[1] [2] [RPOA_BACSU] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. 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 PubMedBACKGROUND: Spx, an ArsC (arsenate reductase) family member, is a global transcriptional regulator of the microbial stress response and is highly conserved amongst Gram-positive bacteria. Bacillus subtilis Spx protein exerts positive and negative control of transcription through its interaction with the C-terminal domain of the RNA polymerase (RNAP) alpha subunit (alphaCTD). Spx activates trxA (thioredoxin) and trxB (thioredoxin reductase) in response to thiol stress, and bears an N-terminal C10XXC13 redox disulfide center that is oxidized in active Spx. METHODOLOGY/PRINCIPAL FINDINGS: The structure of mutant Spx(C10S) showed a change in the conformation of helix alpha4. Amino acid substitutions R60E and K62E within and adjacent to helix alpha4 conferred defects in Spx-activated transcription but not Spx-dependent repression. Electrophoretic mobility-shift assays showed alphaCTD interaction with trxB promoter DNA, but addition of Spx generated a supershifted complex that was disrupted in the presence of reductant (DTT). Interaction of alphaCTD/Spx complex with promoter DNA required the cis-acting elements -45AGCA-42 and -34AGCG-31 of the trxB promoter. The Spx(G52R) mutant, defective in alphaCTD binding, did not interact with the alphaCTD-trxB complex. Spx(R60E) not only failed to complex with alphaCTD-trxB, but also disrupted alphaCTD-trxB DNA interaction. CONCLUSIONS/SIGNIFICANCE: The results show that Spx and alphaCTD form a complex that recognizes the promoter DNA of an Spx-controlled gene. A conformational change during oxidation of Spx to the disulfide form likely alters the structure of Spx alpha helix alpha4, which contains residues that function in transcriptional activation and alphaCTD/Spx-promoter interaction. The results suggest that one of these residues, R60 of the alpha4 region of oxidized Spx, functions in alphaCTD/Spx-promoter contact but not in alphaCTD interaction. Promoter recognition by a complex of Spx and the C-terminal domain of the RNA polymerase alpha subunit.,Nakano MM, Lin A, Zuber CS, Newberry KJ, Brennan RG, Zuber P PLoS One. 2010 Jan 13;5(1):e8664. PMID:20084284[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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