4nqw: Difference between revisions
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==Structure of Mycobacterium tuberculosis extracytoplasmic function sigma factor SigK in complex with the cytosolic domain of its cognate anti-sigma factor RskA== | |||
<StructureSection load='4nqw' size='340' side='right'caption='[[4nqw]], [[Resolution|resolution]] 2.40Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4nqw]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=3vdo 3vdo]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4NQW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4NQW FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CD:CADMIUM+ION'>CD</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=4nqw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4nqw OCA], [https://pdbe.org/4nqw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4nqw RCSB], [https://www.ebi.ac.uk/pdbsum/4nqw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4nqw ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/SIGK_MYCTU SIGK_MYCTU] Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. Sigma-K controls genes such as mpt70 and mpt83. | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The host-pathogen interactions in Mycobacterium tuberculosis infection are significantly influenced by redox stimuli and alterations in the levels of secreted antigens. The extracytoplasmic function (ECF) sigma factor sigma(K) governs the transcription of the serodominant antigens MPT70 and MPT83. The cellular levels of sigma(K) are regulated by the membrane-associated anti-sigma(K) (RskA) that localizes sigma(K) in an inactive complex. The crystal structure of M. tuberculosis sigma(K) in complex with the cytosolic domain of RskA (RskAcyto) revealed a disulfide bridge in the -35 promoter-interaction region of sigma(K). Biochemical experiments reveal that the redox potential of the disulfide-forming cysteines in sigma(K) is consistent with its role as a sensor. The disulfide bond in sigma(K) influences the stability of the sigma(K)-RskAcyto complex but does not interfere with sigma(K)-promoter DNA interactions. It is noted that these disulfide-forming cysteines are conserved across homologues, suggesting that this could be a general mechanism for redox-sensitive transcription regulation. | |||
Structural basis for the redox sensitivity of the Mycobacterium tuberculosis SigK-RskA sigma-anti-sigma complex.,Shukla J, Gupta R, Thakur KG, Gokhale R, Gopal B Acta Crystallogr D Biol Crystallogr. 2014 Apr 1;70(Pt 4):1026-36. doi:, 10.1107/S1399004714000121. Epub 2014 Mar 19. PMID:24699647<ref>PMID:24699647</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 4nqw" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Sigma factor 3D structures|Sigma factor 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Mycobacterium tuberculosis]] | |||
[[Category: Gopal B]] | |||
[[Category: Shukla JK]] | |||
Latest revision as of 11:43, 11 January 2023
Structure of Mycobacterium tuberculosis extracytoplasmic function sigma factor SigK in complex with the cytosolic domain of its cognate anti-sigma factor RskAStructure of Mycobacterium tuberculosis extracytoplasmic function sigma factor SigK in complex with the cytosolic domain of its cognate anti-sigma factor RskA
Structural highlights
FunctionSIGK_MYCTU Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. Sigma-K controls genes such as mpt70 and mpt83. Publication Abstract from PubMedThe host-pathogen interactions in Mycobacterium tuberculosis infection are significantly influenced by redox stimuli and alterations in the levels of secreted antigens. The extracytoplasmic function (ECF) sigma factor sigma(K) governs the transcription of the serodominant antigens MPT70 and MPT83. The cellular levels of sigma(K) are regulated by the membrane-associated anti-sigma(K) (RskA) that localizes sigma(K) in an inactive complex. The crystal structure of M. tuberculosis sigma(K) in complex with the cytosolic domain of RskA (RskAcyto) revealed a disulfide bridge in the -35 promoter-interaction region of sigma(K). Biochemical experiments reveal that the redox potential of the disulfide-forming cysteines in sigma(K) is consistent with its role as a sensor. The disulfide bond in sigma(K) influences the stability of the sigma(K)-RskAcyto complex but does not interfere with sigma(K)-promoter DNA interactions. It is noted that these disulfide-forming cysteines are conserved across homologues, suggesting that this could be a general mechanism for redox-sensitive transcription regulation. Structural basis for the redox sensitivity of the Mycobacterium tuberculosis SigK-RskA sigma-anti-sigma complex.,Shukla J, Gupta R, Thakur KG, Gokhale R, Gopal B Acta Crystallogr D Biol Crystallogr. 2014 Apr 1;70(Pt 4):1026-36. doi:, 10.1107/S1399004714000121. Epub 2014 Mar 19. PMID:24699647[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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