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4zcu

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Revision as of 13:30, 4 May 2017

Structure of calcium-bound regulatory domain of the human ATP-Mg/Pi carrier in the P2 form

Structural highlights

4zcu is a 3 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[SCMC1_HUMAN] Calcium-dependent mitochondrial solute carrier. Mitochondrial solute carriers shuttle metabolites, nucleotides, and cofactors through the mitochondrial inner membrane. May act as a ATP-Mg/Pi exchanger that mediates the transport of Mg-ATP in exchange for phosphate, catalyzing the net uptake or efflux of adenine nucleotides into or from the mitochondria.^[1]

Publication Abstract from PubMed

The mitochondrial ATP-Mg/Pi carrier imports adenine nucleotides from the cytosol into the mitochondrial matrix and exports phosphate. The carrier is regulated by the concentration of cytosolic calcium, altering the size of the adenine nucleotide pool in the mitochondrial matrix in response to energetic demands. The protein consists of three domains; (i) the N-terminal regulatory domain, which is formed of two pairs of fused calcium-binding EF-hands, (ii) the C-terminal mitochondrial carrier domain, which is involved in transport, and (iii) a linker region with an amphipathic alpha-helix of unknown function. The mechanism by which calcium binding to the regulatory domain modulates substrate transport in the carrier domain has not been resolved. Here, we present two new crystal structures of the regulatory domain of the human isoform 1. Careful analysis by SEC confirmed that although the regulatory domain crystallised as dimers, full-length ATP-Mg/Pi carrier is monomeric. Therefore, the ATP-Mg/Pi carrier must have a different mechanism of calcium regulation than the architecturally related aspartate/glutamate carrier, which is dimeric. The structure showed that an amphipathic alpha-helix is bound to the regulatory domain in a hydrophobic cleft of EF-hand 3/4. Detailed bioinformatics analyses of different EF-hand states indicate that upon release of calcium, EF-hands close, meaning that the regulatory domain would release the amphipathic alpha-helix. We propose a mechanism for ATP-Mg/Pi carriers in which the amphipathic alpha-helix becomes mobile upon release of calcium and could block the transport of substrates across the mitochondrial inner membrane.

Calcium-induced conformational changes in the regulatory domain of the human mitochondrial ATP-Mg/Pi carrier.,Harborne SP, Ruprecht JJ, Kunji ER Biochim Biophys Acta. 2015 Jul 9;1847(10):1245-1253. doi:, 10.1016/j.bbabio.2015.07.002. PMID:26164100^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Fiermonte G, De Leonardis F, Todisco S, Palmieri L, Lasorsa FM, Palmieri F. Identification of the mitochondrial ATP-Mg/Pi transporter. Bacterial expression, reconstitution, functional characterization, and tissue distribution. J Biol Chem. 2004 Jul 16;279(29):30722-30. Epub 2004 Apr 29. PMID:15123600 doi:http://dx.doi.org/10.1074/jbc.M400445200
↑ Harborne SP, Ruprecht JJ, Kunji ER. Calcium-induced conformational changes in the regulatory domain of the human mitochondrial ATP-Mg/Pi carrier. Biochim Biophys Acta. 2015 Jul 9;1847(10):1245-1253. doi:, 10.1016/j.bbabio.2015.07.002. PMID:26164100 doi:http://dx.doi.org/10.1016/j.bbabio.2015.07.002

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4zcu"

@@ Line 1: / Line 1: @@
 ==Structure of calcium-bound regulatory domain of the human ATP-Mg/Pi carrier in the P2 form==
 <StructureSection load='4zcu' size='340' side='right' caption='[[4zcu]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
@@ Line 4: / Line 5: @@
 <table><tr><td colspan='2'>[[4zcu]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ZCU OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4ZCU 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=GOL:GLYCEROL'>GOL</scene>, <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=4zcu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4zcu OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4zcu RCSB], [http://www.ebi.ac.uk/pdbsum/4zcu PDBsum]</span></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=4zcu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4zcu OCA], [http://pdbe.org/4zcu PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4zcu RCSB], [http://www.ebi.ac.uk/pdbsum/4zcu PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4zcu ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 16: / Line 17: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 4zcu" style="background-color:#fffaf0;"></div>
 == References ==
 <references/>

4zcu

From Proteopedia

Revision as of 13:30, 4 May 2017

Structure of calcium-bound regulatory domain of the human ATP-Mg/Pi carrier in the P2 form

Structural highlights

Function

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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