4arh: Difference between revisions
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==X ray structure of the periplasmic zinc binding protein ZinT from Salmonella enterica== | |||
<StructureSection load='4arh' size='340' side='right' caption='[[4arh]], [[Resolution|resolution]] 2.30Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4arh]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Salmonella_enterica_subsp._enterica_serovar_4,5,12:i:-_str._cvm23701 Salmonella enterica subsp. enterica serovar 4,5,12:i:- str. cvm23701]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ARH OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4ARH FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></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=4arh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4arh OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4arh RCSB], [http://www.ebi.ac.uk/pdbsum/4arh PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
BACKGROUND: In Gram-negative bacteria the ZnuABC transporter ensures adequate zinc import in Zn(II)-poor environments, like those encountered by pathogens within the infected host. Recently, the metal-binding protein ZinT was suggested to operate as an accessory component of ZnuABC in periplasmic zinc recruitment. Since ZinT is known to form a ZinT-ZnuA complex in the presence of Zn(II) it was proposed to transfer Zn(II) to ZnuA. The present work was undertaken to test this claim. METHODS: ZinT and its structural relationship with ZnuA have been characterized by multiple biophysical techniques (X-ray crystallography, SAXS, analytical ultracentrifugation, fluorescence spectroscopy). RESULTS: The metal-free and metal-bound crystal structures of Salmonella enterica ZinT show one Zn(II) binding site and limited structural changes upon metal removal. Spectroscopic titrations with Zn(II) yield a KD value of 22+/-2nM for ZinT, while those with ZnuA point to one high affinity (KD<20nM) and one low affinity Zn(II) binding site (KD in the micromolar range). Sedimentation velocity experiments established that Zn(II)-bound ZinT interacts with ZnuA, whereas apo-ZinT does not. The model of the ZinT-ZnuA complex derived from small angle X-ray scattering experiments points to a disposition that favors metal transfer as the metal binding cavities of the two proteins face each other. CONCLUSIONS: ZinT acts as a Zn(II)-buffering protein that delivers Zn(II) to ZnuA. GENERAL SIGNIFICANCE: Knowledge of the ZinT-ZnuA relationship is crucial for understanding bacterial Zn(II) uptake. | |||
The Salmonella enterica ZinT structure, zinc affinity and interaction with the high-affinity uptake protein ZnuA provide insight into the management of periplasmic zinc.,Ilari A, Alaleona F, Tria G, Petrarca P, Battistoni A, Zamparelli C, Verzili D, Falconi M, Chiancone E Biochim Biophys Acta. 2014 Jan;1840(1):535-44. doi: 10.1016/j.bbagen.2013.10.010., Epub 2013 Oct 12. PMID:24128931<ref>PMID:24128931</ref> | |||
== | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Salmonella enterica subsp. enterica serovar 4,5,12:i:- str. cvm23701]] | [[Category: Salmonella enterica subsp. enterica serovar 4,5,12:i:- str. cvm23701]] | ||
[[Category: Alaleona, F | [[Category: Alaleona, F]] | ||
[[Category: Battistoni, A | [[Category: Battistoni, A]] | ||
[[Category: Chiancone, E | [[Category: Chiancone, E]] | ||
[[Category: Ilari, A | [[Category: Ilari, A]] | ||
[[Category: Petrarca, P | [[Category: Petrarca, P]] | ||
[[Category: Metal binding protein]] | [[Category: Metal binding protein]] | ||
[[Category: Periplasmic protein]] | [[Category: Periplasmic protein]] | ||
