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| | <StructureSection load='4rr0' size='340' side='right'caption='[[4rr0]], [[Resolution|resolution]] 3.05Å' scene=''> | | <StructureSection load='4rr0' size='340' side='right'caption='[[4rr0]], [[Resolution|resolution]] 3.05Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4rr0]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4RR0 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4RR0 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4rr0]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4RR0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4RR0 FirstGlance]. <br> |
| - | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1vcw|1vcw]]</td></tr> | + | </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=4rr0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4rr0 OCA], [https://pdbe.org/4rr0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4rr0 RCSB], [https://www.ebi.ac.uk/pdbsum/4rr0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4rr0 ProSAT]</span></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">degS, P12B_c3347 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</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=4rr0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4rr0 OCA], [http://pdbe.org/4rr0 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4rr0 RCSB], [http://www.ebi.ac.uk/pdbsum/4rr0 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4rr0 ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/DEGS_ECOLI DEGS_ECOLI] When heat shock or other environmental stresses disrupt protein folding in the periplasm, DegS senses the accumulation of unassembled outer membrane porins (OMPs) and then initiates RseA (anti sigma-E factor) degradation by cleaving it in its periplasmic domain, making it an attractive substrate for subsequent cleavage by RseP. This cascade that ultimately leads to the sigma-E-driven expression of a variety of factors dealing with folding stress in the periplasm and OMP assembly.<ref>PMID:12183369</ref> <ref>PMID:19695325</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
| - | Gram-negative bacteria respond to misfolded proteins in the cell envelope with the sigmaE-driven expression of periplasmic proteases/chaperones. Activation of sigmaE is controlled by a proteolytic cascade that is initiated by the DegS protease. DegS senses misfolded protein in the periplasm, undergoes autoactivation, and cleaves the antisigma factor RseA. Here, we present the crystal structures of three distinct states of DegS from E. coli. DegS alone exists in a catalytically inactive form. Binding of stress-signaling peptides to its PDZ domain induces a series of conformational changes that activates protease function. Backsoaking of crystals containing the DegS-activator complex revealed the presence of an active/inactive hybrid structure and demonstrated the reversibility of activation. Taken together, the structural data illustrate in molecular detail how DegS acts as a periplasmic stress sensor. Our results suggest a novel regulatory role for PDZ domains and unveil a novel mechanism of reversible protease activation.
| + | In E. coli, outer-membrane stress causes a transcriptional response through a signaling cascade initiated by DegS cleavage of a transmembrane antisigma factor. Each subunit of DegS, an HtrA-family protease, contains a protease domain and a PDZ domain. The trimeric protease domain is autoinhibited by the unliganded PDZ domains. Allosteric activation requires binding of unassembled outer-membrane proteins (OMPs) to the PDZ domains and protein substrate binding. Here, we identify a set of DegS residues that cluster together at subunit-subunit interfaces in the trimer, link the active sites and substrate binding sites, and are crucial for stabilizing the active enzyme conformation in response to OMP signaling. These residues are conserved across the HtrA-protease family, including orthologs linked to human disease, supporting a common mechanism of allosteric activation. Indeed, mutation of residues at homologous positions in the DegP quality-control protease also eliminates allosteric activation. |
| | | | |
| - | Crystal structure of the DegS stress sensor: How a PDZ domain recognizes misfolded protein and activates a protease.,Wilken C, Kitzing K, Kurzbauer R, Ehrmann M, Clausen T Cell. 2004 May 14;117(4):483-94. PMID:15137941<ref>PMID:15137941</ref>
| + | A Conserved Activation Cluster Is Required for Allosteric Communication in HtrA-Family Proteases.,de Regt AK, Kim S, Sohn J, Grant RA, Baker TA, Sauer RT Structure. 2015 Mar 3;23(3):517-26. doi: 10.1016/j.str.2015.01.012. Epub 2015 Feb, 19. PMID:25703375<ref>PMID:25703375</ref> |
| | | | |
| | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bacillus coli migula 1895]] | + | [[Category: Escherichia coli]] |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Grant, R A]] | + | [[Category: Grant RA]] |
| - | [[Category: Sauer, R T]] | + | [[Category: Sauer RT]] |
| - | [[Category: Htra]]
| + | |
| - | [[Category: Hydrolase]]
| + | |
| - | [[Category: Pdz]]
| + | |
| - | [[Category: Protein quality control]]
| + | |
| - | [[Category: Stress response]]
| + | |
| - | [[Category: Upr]]
| + | |
| Structural highlights
Function
DEGS_ECOLI When heat shock or other environmental stresses disrupt protein folding in the periplasm, DegS senses the accumulation of unassembled outer membrane porins (OMPs) and then initiates RseA (anti sigma-E factor) degradation by cleaving it in its periplasmic domain, making it an attractive substrate for subsequent cleavage by RseP. This cascade that ultimately leads to the sigma-E-driven expression of a variety of factors dealing with folding stress in the periplasm and OMP assembly.[1] [2]
Publication Abstract from PubMed
In E. coli, outer-membrane stress causes a transcriptional response through a signaling cascade initiated by DegS cleavage of a transmembrane antisigma factor. Each subunit of DegS, an HtrA-family protease, contains a protease domain and a PDZ domain. The trimeric protease domain is autoinhibited by the unliganded PDZ domains. Allosteric activation requires binding of unassembled outer-membrane proteins (OMPs) to the PDZ domains and protein substrate binding. Here, we identify a set of DegS residues that cluster together at subunit-subunit interfaces in the trimer, link the active sites and substrate binding sites, and are crucial for stabilizing the active enzyme conformation in response to OMP signaling. These residues are conserved across the HtrA-protease family, including orthologs linked to human disease, supporting a common mechanism of allosteric activation. Indeed, mutation of residues at homologous positions in the DegP quality-control protease also eliminates allosteric activation.
A Conserved Activation Cluster Is Required for Allosteric Communication in HtrA-Family Proteases.,de Regt AK, Kim S, Sohn J, Grant RA, Baker TA, Sauer RT Structure. 2015 Mar 3;23(3):517-26. doi: 10.1016/j.str.2015.01.012. Epub 2015 Feb, 19. PMID:25703375[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Alba BM, Leeds JA, Onufryk C, Lu CZ, Gross CA. DegS and YaeL participate sequentially in the cleavage of RseA to activate the sigma(E)-dependent extracytoplasmic stress response. Genes Dev. 2002 Aug 15;16(16):2156-68. PMID:12183369 doi:10.1101/gad.1008902
- ↑ Meltzer M, Hasenbein S, Mamant N, Merdanovic M, Poepsel S, Hauske P, Kaiser M, Huber R, Krojer T, Clausen T, Ehrmann M. Structure, function and regulation of the conserved serine proteases DegP and DegS of Escherichia coli. Res Microbiol. 2009 Nov;160(9):660-6. doi: 10.1016/j.resmic.2009.07.012. Epub, 2009 Aug 18. PMID:19695325 doi:10.1016/j.resmic.2009.07.012
- ↑ de Regt AK, Kim S, Sohn J, Grant RA, Baker TA, Sauer RT. A conserved activation cluster is required for allosteric communication in HtrA-family proteases. Structure. 2015 Mar 3;23(3):517-526. PMID:25703375 doi:10.1016/j.str.2015.01.012
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