View source for 4hmp


==Crystal structure of iron uptake ABC transporter substrate-binding protein PiaA from Streptococcus pneumoniae TIGR4==
<StructureSection load='4hmp' size='340' side='right'caption='[[4hmp]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4hmp]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptococcus_pneumoniae_TIGR4 Streptococcus pneumoniae TIGR4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HMP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HMP FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.7&#8491;</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>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene>, <scene name='pdbligand=PG4:TETRAETHYLENE+GLYCOL'>PG4</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=4hmp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hmp OCA], [https://pdbe.org/4hmp PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hmp RCSB], [https://www.ebi.ac.uk/pdbsum/4hmp PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hmp ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A0A0H2UPT5_STRPN A0A0H2UPT5_STRPN] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Iron scarcity is one of the nutrition limitations that the Gram-positive infectious pathogens Streptococcus pneumoniae encounter in the human host. To guarantee sufficient iron supply, the ATP binding cassette (ABC) transporter Pia is employed to uptake iron chelated by hydroxamate siderophore, via the membrane-anchored substrate-binding protein PiaA. The high affinity towards ferrichrome enables PiaA to capture iron at a very low concentration in the host. We presented here the crystal structures of PiaA in both apo and ferrichrome-complexed forms at 2.7 and 2.1 A resolution, respectively. Similar to other class III substrate binding proteins, PiaA is composed of an N-terminal and a C-terminal domain bridged by an alpha-helix. At the inter-domain cleft, a molecule of ferrichrome is stabilized by a number of highly conserved residues. Upon ferrichrome binding, two highly flexible segments at the entrance of the cleft undergo significant conformational changes, indicating their contribution to the binding and/or release of ferrichrome. Superposition to the structure of Escherichia coli ABC transporter BtuF enabled us to define two conserved residues: Glu119 and Glu262, which were proposed to form salt bridges with two arginines of the permease subunits. Further structure-based sequence alignment revealed that the ferrichrome binding pattern is highly conserved in a series of PiaA homologs encoded by both Gram-positive and negative bacteria, which were predicted to be sensitive to albomycin, a sideromycin antibiotic derived from ferrichrome.

Structures of Streptococcus pneumoniae PiaA and Its Complex with Ferrichrome Reveal Insights into the Substrate Binding and Release of High Affinity Iron Transporters.,Cheng W, Li Q, Jiang YL, Zhou CZ, Chen Y PLoS One. 2013;8(8):e71451. doi: 10.1371/journal.pone.0071451. PMID:23951167<ref>PMID:23951167</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4hmp" style="background-color:#fffaf0;"></div>

==See Also==
*[[ABC transporter 3D structures|ABC transporter 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptococcus pneumoniae TIGR4]]
[[Category: Chen Y]]
[[Category: Cheng W]]
[[Category: Jiang Y-L]]
[[Category: Li Q]]
[[Category: Zhou C-Z]]