2k78: Difference between revisions

<table><tr><td colspan='2'>[[2k78]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Staphylococcus_aureus_subsp._aureus_MW2 Staphylococcus aureus subsp. aureus MW2]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2K78 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2K78 FirstGlance]. <br>

</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, models</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=2k78 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2k78 OCA], [https://pdbe.org/2k78 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2k78 RCSB], [https://www.ebi.ac.uk/pdbsum/2k78 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2k78 ProSAT]</span></td></tr>

[https://www.uniprot.org/uniprot/ISDC_STAAW ISDC_STAAW] 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 (By similarity). 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.<ref>PMID:18184657</ref>

    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/k7/2k78_consurf.spt"</scriptWhenChecked>

    <text>to colour the structure by Evolutionary Conservation</text>

</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=2k78 ConSurf].

Staphylococcus aureus scavenges heme-iron from host hemoproteins using iron-regulated surface determinant (Isd) proteins. IsdC is the central conduit through which heme is passed across the cell wall and binds this molecule using a NEAr Transporter (NEAT) domain. NMR spectroscopy was used to determine the structure of IsdC in complex with a heme analog, zinc-substituted protoporphyrin IX (ZnPPIX). The backbone coordinates of the ensemble of conformers representing the structure exhibit a root mean square deviation to the mean structure of 0.53 +/- 0.11 angstroms. IsdC partially buries protoporphyrin within a large hydrophobic pocket that is located at the end of its beta-barrel structure. The central metal ion of the analog adopts a pentacoordinate geometry in which a highly conserved tyrosine residue serves as a proximal ligand. Consistent with the structure and its role in heme transfer across the cell wall, we show that IsdC weakly binds heme (K(D) = 0.34 +/- 0.12 microm) and that ZnPPIX rapidly dissociates from the protein at a rate of 126 +/- 30 s(-1). NMR studies of the apo-form of IsdC reveal that a 3(10) helix within the binding pocket undergoes a flexible to rigid transition as heme is captured. This structural plasticity may increase the efficiency of heme transfer across the cell wall by facilitating protein-protein interactions between apoIsdC and upstream hemoproteins.

The IsdC protein from Staphylococcus aureus uses a flexible binding pocket to capture heme.,Villareal VA, Pilpa RM, Robson SA, Fadeev EA, Clubb RT J Biol Chem. 2008 Nov 14;283(46):31591-600. Epub 2008 Aug 20. PMID:18715872<ref>PMID:18715872</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

</div>

<div class="pdbe-citations 2k78" style="background-color:#fffaf0;"></div>

== References ==

<references/>

</StructureSection>

[[Category: Large Structures]]

[[Category: Staphylococcus aureus subsp. aureus MW2]]

[[Category: Clubb RT]]

[[Category: Fadeev EA]]

[[Category: Pilpa RM]]

[[Category: Robson SA]]

[[Category: Villareal VA]]