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| | ==Mycobacterium tuberculosis RbpA-SID in complex with SigmaA domain 2== | | ==Mycobacterium tuberculosis RbpA-SID in complex with SigmaA domain 2== |
| - | <StructureSection load='4x8k' size='340' side='right' caption='[[4x8k]], [[Resolution|resolution]] 2.20Å' scene=''> | + | <StructureSection load='4x8k' size='340' side='right'caption='[[4x8k]], [[Resolution|resolution]] 2.20Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4x8k]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_tuberculosis"_(zopf_1883)_klein_1884 "bacillus tuberculosis" (zopf 1883) klein 1884]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4X8K OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4X8K FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4x8k]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4X8K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4X8K FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">sigA, mysA, rpoD, rpoV, MT2777 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1773 "Bacillus tuberculosis" (Zopf 1883) Klein 1884]), rbpA, MT2110 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1773 "Bacillus tuberculosis" (Zopf 1883) Klein 1884])</td></tr>
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4x8k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4x8k OCA], [https://pdbe.org/4x8k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4x8k RCSB], [https://www.ebi.ac.uk/pdbsum/4x8k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4x8k ProSAT]</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=4x8k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4x8k OCA], [http://pdbe.org/4x8k PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4x8k RCSB], [http://www.ebi.ac.uk/pdbsum/4x8k PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4x8k ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/SIGA_MYCTO SIGA_MYCTO]] Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This sigma factor is the primary sigma factor during exponential growth.[HAMAP-Rule:MF_00963] [[http://www.uniprot.org/uniprot/RBPA_MYCTO RBPA_MYCTO]] Binds to RNA polymerase (RNAP), stimulating transcription from principal, but not alternative sigma factor promoters. | + | [https://www.uniprot.org/uniprot/SIGA_MYCTU SIGA_MYCTU] Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This sigma factor is the primary sigma factor during exponential growth (Probable).<ref>PMID:12354223</ref> <ref>PMID:20729364</ref> <ref>PMID:22570422</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </div> | | </div> |
| | <div class="pdbe-citations 4x8k" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 4x8k" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[Sigma factor 3D structures|Sigma factor 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Campbell, E A]] | + | [[Category: Large Structures]] |
| - | [[Category: Darst, S A]] | + | [[Category: Mycobacterium tuberculosis]] |
| - | [[Category: Flack, J E]] | + | [[Category: Campbell EA]] |
| - | [[Category: Hubin, E A]] | + | [[Category: Darst SA]] |
| - | [[Category: Paget, M S]] | + | [[Category: Flack JE]] |
| - | [[Category: Tabib-Salazar, A]] | + | [[Category: Hubin EA]] |
| - | [[Category: Sigma factor]] | + | [[Category: Paget MS]] |
| - | [[Category: Transcription activator]] | + | [[Category: Tabib-Salazar A]] |
| Structural highlights
Function
SIGA_MYCTU Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This sigma factor is the primary sigma factor during exponential growth (Probable).[1] [2] [3]
Publication Abstract from PubMed
Gene expression is highly regulated at the step of transcription initiation, and transcription activators play a critical role in this process. RbpA, an actinobacterial transcription activator that is essential in Mycobacterium tuberculosis (Mtb), binds selectively to group 1 and certain group 2 sigma-factors. To delineate the molecular mechanism of RbpA, we show that the Mtb RbpA sigma-interacting domain (SID) and basic linker are sufficient for transcription activation. We also present the crystal structure of the Mtb RbpA-SID in complex with domain 2 of the housekeeping sigma-factor, sigma(A). The structure explains the basis of sigma-selectivity by RbpA, showing that RbpA interacts with conserved regions of sigma(A) as well as the nonconserved region (NCR), which is present only in housekeeping sigma-factors. Thus, the structure is the first, to our knowledge, to show a protein interacting with the NCR of a sigma-factor. We confirm the basis of selectivity and the observed interactions using mutagenesis and functional studies. In addition, the structure allows for a model of the RbpA-SID in the context of a transcription initiation complex. Unexpectedly, the structural modeling suggests that RbpA contacts the promoter DNA, and we present in vivo and in vitro studies supporting this finding. Our combined data lead to a better understanding of the mechanism of RbpA function as a transcription activator.
Structural, functional, and genetic analyses of the actinobacterial transcription factor RbpA.,Hubin EA, Tabib-Salazar A, Humphrey LJ, Flack JE, Olinares PD, Darst SA, Campbell EA, Paget MS Proc Natl Acad Sci U S A. 2015 Jun 9;112(23):7171-6. doi:, 10.1073/pnas.1504942112. Epub 2015 May 26. PMID:26040003[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Beaucher J, Rodrigue S, Jacques PE, Smith I, Brzezinski R, Gaudreau L. Novel Mycobacterium tuberculosis anti-sigma factor antagonists control sigmaF activity by distinct mechanisms. Mol Microbiol. 2002 Sep;45(6):1527-40. PMID:12354223
- ↑ Hartkoorn RC, Sala C, Magnet SJ, Chen JM, Pojer F, Cole ST. Sigma factor F does not prevent rifampin inhibition of RNA polymerase or cause rifampin tolerance in Mycobacterium tuberculosis. J Bacteriol. 2010 Oct;192(20):5472-9. doi: 10.1128/JB.00687-10. Epub 2010 Aug 20. PMID:20729364 doi:http://dx.doi.org/10.1128/JB.00687-10
- ↑ Hu Y, Morichaud Z, Chen S, Leonetti JP, Brodolin K. Mycobacterium tuberculosis RbpA protein is a new type of transcriptional activator that stabilizes the sigma A-containing RNA polymerase holoenzyme. Nucleic Acids Res. 2012 Aug;40(14):6547-57. doi: 10.1093/nar/gks346. Epub 2012, May 8. PMID:22570422 doi:http://dx.doi.org/10.1093/nar/gks346
- ↑ Hubin EA, Tabib-Salazar A, Humphrey LJ, Flack JE, Olinares PD, Darst SA, Campbell EA, Paget MS. Structural, functional, and genetic analyses of the actinobacterial transcription factor RbpA. Proc Natl Acad Sci U S A. 2015 Jun 9;112(23):7171-6. doi:, 10.1073/pnas.1504942112. Epub 2015 May 26. PMID:26040003 doi:http://dx.doi.org/10.1073/pnas.1504942112
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