2o6p: Difference between revisions
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==Crystal Structure of the heme-IsdC complex== | ==Crystal Structure of the heme-IsdC complex== | ||
<StructureSection load='2o6p' size='340' side='right' caption='[[2o6p]], [[Resolution|resolution]] 1.50Å' scene=''> | <StructureSection load='2o6p' size='340' side='right'caption='[[2o6p]], [[Resolution|resolution]] 1.50Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[2o6p]] is a 2 chain structure with sequence from [ | <table><tr><td colspan='2'>[[2o6p]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Staphylococcus_aureus_subsp._aureus_N315 Staphylococcus aureus subsp. aureus N315]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2O6P OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2O6P FirstGlance]. <br> | ||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.5Å</td></tr> | ||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</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=2o6p FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2o6p OCA], [https://pdbe.org/2o6p PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2o6p RCSB], [https://www.ebi.ac.uk/pdbsum/2o6p PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2o6p ProSAT]</span></td></tr> | |||
</table> | </table> | ||
== Function == | == Function == | ||
[ | [https://www.uniprot.org/uniprot/ISDC_STAA8 ISDC_STAA8] Involved in heme (porphyrin) scavenging. Binds hemoglobin and almost exclusively free-base protoporphyrin IX. Probably has a role as the central conduit of the isd heme uptake system, i.e. mediates the transfer of the iron-containing nutrient from IsdABH to the membrane translocation system IsdDEF. Hemin-free IsdC (apo-IsdC) acquires hemin from hemin-containing IsdA (holo-IsdA) probably through the activated holo-IsdA-apo-IsdC complex and due to the higher affinity of apo-IsdC for the cofactor. The reaction is reversible (By similarity).<ref>PMID:15240116</ref> <ref>PMID:17287214</ref> | ||
== Evolutionary Conservation == | == Evolutionary Conservation == | ||
[[Image:Consurf_key_small.gif|200px|right]] | [[Image:Consurf_key_small.gif|200px|right]] | ||
Check<jmol> | Check<jmol> | ||
<jmolCheckbox> | <jmolCheckbox> | ||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/o6/2o6p_consurf.spt"</scriptWhenChecked> | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/o6/2o6p_consurf.spt"</scriptWhenChecked> | ||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | ||
<text>to colour the structure by Evolutionary Conservation</text> | <text>to colour the structure by Evolutionary Conservation</text> | ||
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</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/main_output.php?pdb_ID=2o6p ConSurf]. | </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/main_output.php?pdb_ID=2o6p ConSurf]. | ||
<div style="clear:both"></div> | <div style="clear:both"></div> | ||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Pathogens such as Staphylococcus aureus require iron to survive and have evolved specialized proteins to steal heme from their host. IsdC is the central conduit of the Isd (iron-regulated surface determinant) multicomponent heme uptake machinery; staphylococcal cell-surface proteins such as IsdA, IsdB, and IsdH are thought to funnel their molecular cargo to IsdC, which then mediates the transfer of the iron-containing nutrient to the membrane translocation system IsdDEF. The structure of the heme-IsdC complex reveals a novel heme site within an immunoglobulin-like domain and sheds light on its binding mechanism. The folding topology is reminiscent of the architecture of cytochrome f, cellobiose dehydrogenase, and ethylbenzene dehydrogenase; in these three proteins, the heme is bound in an equivalent position, but interestingly, IsdC features a distinct binding pocket with the ligand located next to the hydrophobic core of the beta-sandwich. The iron is coordinated with a tyrosine surrounded by several non-polar side chains that cluster into a tightly packed proximal side. On the other hand, the distal side is relatively exposed with a short helical peptide segment that acts as a lip clasping onto almost half of the porphyrin plane. This structural feature is argued to play a role in the mechanism of binding and release by switching to an open conformation and thus loosening the interactions holding the heme. The structure of the heme-IsdC complex provides a template for the understanding of other proteins, such as IsdA, IsdB, and IsdH, that contain the same heme-binding module as IsdC, known as the NEAT (near transporter) domain. | |||
Crystal structure of the heme-IsdC complex, the central conduit of the Isd iron/heme uptake system in Staphylococcus aureus.,Sharp KH, Schneider S, Cockayne A, Paoli M J Biol Chem. 2007 Apr 6;282(14):10625-31. Epub 2007 Feb 7. PMID:17287214<ref>PMID:17287214</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2o6p" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: Cockayne | [[Category: Staphylococcus aureus subsp. aureus N315]] | ||
[[Category: Paoli | [[Category: Cockayne A]] | ||
[[Category: Schneider | [[Category: Paoli M]] | ||
[[Category: Sharp | [[Category: Schneider S]] | ||
[[Category: Sharp KH]] | |||
Latest revision as of 03:15, 28 December 2023
Crystal Structure of the heme-IsdC complexCrystal Structure of the heme-IsdC complex
Structural highlights
FunctionISDC_STAA8 Involved in heme (porphyrin) scavenging. Binds hemoglobin and almost exclusively free-base protoporphyrin IX. Probably has a role as the central conduit of the isd heme uptake system, i.e. mediates the transfer of the iron-containing nutrient from IsdABH to the membrane translocation system IsdDEF. Hemin-free IsdC (apo-IsdC) acquires hemin from hemin-containing IsdA (holo-IsdA) probably through the activated holo-IsdA-apo-IsdC complex and due to the higher affinity of apo-IsdC for the cofactor. The reaction is reversible (By similarity).[1] [2] 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 PubMedPathogens such as Staphylococcus aureus require iron to survive and have evolved specialized proteins to steal heme from their host. IsdC is the central conduit of the Isd (iron-regulated surface determinant) multicomponent heme uptake machinery; staphylococcal cell-surface proteins such as IsdA, IsdB, and IsdH are thought to funnel their molecular cargo to IsdC, which then mediates the transfer of the iron-containing nutrient to the membrane translocation system IsdDEF. The structure of the heme-IsdC complex reveals a novel heme site within an immunoglobulin-like domain and sheds light on its binding mechanism. The folding topology is reminiscent of the architecture of cytochrome f, cellobiose dehydrogenase, and ethylbenzene dehydrogenase; in these three proteins, the heme is bound in an equivalent position, but interestingly, IsdC features a distinct binding pocket with the ligand located next to the hydrophobic core of the beta-sandwich. The iron is coordinated with a tyrosine surrounded by several non-polar side chains that cluster into a tightly packed proximal side. On the other hand, the distal side is relatively exposed with a short helical peptide segment that acts as a lip clasping onto almost half of the porphyrin plane. This structural feature is argued to play a role in the mechanism of binding and release by switching to an open conformation and thus loosening the interactions holding the heme. The structure of the heme-IsdC complex provides a template for the understanding of other proteins, such as IsdA, IsdB, and IsdH, that contain the same heme-binding module as IsdC, known as the NEAT (near transporter) domain. Crystal structure of the heme-IsdC complex, the central conduit of the Isd iron/heme uptake system in Staphylococcus aureus.,Sharp KH, Schneider S, Cockayne A, Paoli M J Biol Chem. 2007 Apr 6;282(14):10625-31. Epub 2007 Feb 7. PMID:17287214[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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