View source for 4mvu


==Structural Basis for Ca2+ Selectivity of a Voltage-gated Calcium Channel==
<StructureSection load='4mvu' size='340' side='right'caption='[[4mvu]], [[Resolution|resolution]] 3.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4mvu]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Aliarcobacter_butzleri_RM4018 Aliarcobacter butzleri RM4018]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4MVU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4MVU 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]] 3.198&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=PX4:1,2-DIMYRISTOYL-SN-GLYCERO-3-PHOSPHOCHOLINE'>PX4</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=4mvu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4mvu OCA], [https://pdbe.org/4mvu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4mvu RCSB], [https://www.ebi.ac.uk/pdbsum/4mvu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4mvu ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A8EVM5_ALIB4 A8EVM5_ALIB4] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Voltage-gated calcium (CaV) channels catalyse rapid, highly selective influx of Ca2+ into cells despite a 70-fold higher extracellular concentration of Na+. How CaV channels solve this fundamental biophysical problem remains unclear. Here we report physiological and crystallographic analyses of a calcium selectivity filter constructed in the homotetrameric bacterial NaV channel NaVAb. Our results reveal interactions of hydrated Ca2+ with two high-affinity Ca2+-binding sites followed by a third lower-affinity site that would coordinate Ca2+ as it moves inward. At the selectivity filter entry, Site 1 is formed by four carboxyl side chains, which have a critical role in determining Ca2+ selectivity. Four carboxyls plus four backbone carbonyls form Site 2, which is targeted by the blocking cations Cd2+ and Mn2+, with single occupancy. The lower-affinity Site 3 is formed by four backbone carbonyls alone, which mediate exit into the central cavity. This pore architecture suggests a conduction pathway involving transitions between two main states with one or two hydrated Ca2+ ions bound in the selectivity filter and supports a 'knock-off' mechanism of ion permeation through a stepwise-binding process. The multi-ion selectivity filter of our CaVAb model establishes a structural framework for understanding the mechanisms of ion selectivity and conductance by vertebrate CaV channels.

Structural basis for Ca selectivity of a voltage-gated calcium channel.,Tang L, Gamal El-Din TM, Payandeh J, Martinez GQ, Heard TM, Scheuer T, Zheng N, Catterall WA Nature. 2013 Nov 24. doi: 10.1038/nature12775. PMID:24270805<ref>PMID:24270805</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4mvu" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Aliarcobacter butzleri RM4018]]
[[Category: Large Structures]]
[[Category: Catterall WA]]
[[Category: Gamal El-Din TM]]
[[Category: Heard TM]]
[[Category: Martinez GQ]]
[[Category: Payandeh J]]
[[Category: Scheuer T]]
[[Category: Tang L]]
[[Category: Zheng N]]