View source for 9fjr


==Cryo-EM structure of Mycobacterium tuberculosis sigma-B RNA polymerase bound to -10 promoter element ssDNA oligo - sigma-B docked conformation==
<StructureSection load='9fjr' size='340' side='right'caption='[[9fjr]], [[Resolution|resolution]] 3.43&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9fjr]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] and [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis_H37Rv Mycobacterium tuberculosis H37Rv]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9FJR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9FJR FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.43&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></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=9fjr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9fjr OCA], [https://pdbe.org/9fjr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9fjr RCSB], [https://www.ebi.ac.uk/pdbsum/9fjr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9fjr ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RPOA_MYCTU RPOA_MYCTU] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.[HAMAP-Rule:MF_00059]<ref>PMID:22570422</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Initiation of transcription requires the formation of the "open" promoter complex (RPo). For this, the sigma subunit of bacterial RNA polymerase (RNAP) binds to the nontemplate strand of the -10 element sequence of promoters and nucleates DNA unwinding. This is accompanied by a cascade of conformational changes on RNAP, the exact mechanics of which remains elusive. Here, using single-molecule Forster resonance energy transfer and cryo-electron microscopy, we explored the conformational landscape of RNAP from the human pathogen Mycobacterium tuberculosis upon binding to a single-stranded DNA (ssDNA) fragment that includes the -10 element sequence (-10 ssDNA). We found that like the transcription activator RNAP-binding protein A, -10 ssDNA induced sigma subunit loading onto the DNA/RNA channels of RNAP. This triggered RNAP clamp closure and unswiveling that are required for RPo formation and RNA synthesis initiation. Our results reveal a mechanism of ssDNA-guided RNAP maturation and identify the sigma subunit as a regulator of RNAP conformational dynamics.

Single-stranded DNA drives sigma subunit loading onto mycobacterial RNA polymerase to unlock initiation-competent conformations.,Vishwakarma RK, Marechal N, Morichaud Z, Blaise M, Margeat E, Brodolin K Nucleic Acids Res. 2025 Apr 10;53(7):gkaf272. doi: 10.1093/nar/gkaf272. PMID:40240004<ref>PMID:40240004</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9fjr" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Mycobacterium tuberculosis H37Rv]]
[[Category: Blaise M]]
[[Category: Brodolin K]]