4mtf

<StructureSection load='4mtf' size='340' side='right' caption='[[4mtf]], [[Resolution|resolution]] 3.20&Aring;' scene=''>

<table><tr><td colspan='2'>[[4mtf]] is a 4 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4MTF OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4MTF FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><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='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4ms2|4ms2]]</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=4mtf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4mtf OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4mtf RCSB], [http://www.ebi.ac.uk/pdbsum/4mtf PDBsum]</span></td></tr>

<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>

== References ==

[[Category: Catterall, W A]]

[[Category: El-Din, T M.Gamal]]

[[Category: Heard, T M]]

[[Category: Martinez, G Q]]

[[Category: Payandeh, J]]

[[Category: Scheuer, T]]

[[Category: Tang, L]]

[[Category: Zheng, N]]

[[Category: Voltage-gated ion channel]]