2qvk
From Proteopedia
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|ACTIVITY= | |ACTIVITY= | ||
|GENE= SLC8A1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9615 Canis lupus familiaris]) | |GENE= SLC8A1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9615 Canis lupus familiaris]) | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[2dpk|2DPK]], [[2fwu|2FWU]], [[2qvm|2QVM]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2qvk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qvk OCA], [http://www.ebi.ac.uk/pdbsum/2qvk PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2qvk RCSB]</span> | ||
}} | }} | ||
| Line 31: | Line 34: | ||
[[Category: sodium calcium exchanger]] | [[Category: sodium calcium exchanger]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 04:53:43 2008'' |
Revision as of 01:53, 31 March 2008
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| , resolution 1.451Å | |||||||
|---|---|---|---|---|---|---|---|
| Gene: | SLC8A1 (Canis lupus familiaris) | ||||||
| Related: | 2DPK, 2FWU, 2QVM
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
The second Ca2+-binding domain of the Na+-Ca2+ exchanger is essential for regulation: crystal structures and mutational analysis
Overview
The Na(+)-Ca(2+) exchanger plays a central role in cardiac contractility by maintaining Ca(2+) homeostasis. Two Ca(2+)-binding domains, CBD1 and CBD2, located in a large intracellular loop, regulate activity of the exchanger. Ca(2+) binding to these regulatory domains activates the transport of Ca(2+) across the plasma membrane. Previously, we solved the structure of CBD1, revealing four Ca(2+) ions arranged in a tight planar cluster. Here, we present structures of CBD2 in the Ca(2+)-bound (1.7-A resolution) and -free (1.4-A resolution) conformations. Like CBD1, CBD2 has a classical Ig fold but coordinates only two Ca(2+) ions in primary and secondary Ca(2+) sites. In the absence of Ca(2+), Lys(585) stabilizes the structure by coordinating two acidic residues (Asp(552) and Glu(648)), one from each of the Ca(2+)-binding sites, and prevents a substantial protein unfolding. We have mutated all of the acidic residues that coordinate the Ca(2+) ions and have examined the effects of these mutations on regulation of exchange activity. Three mutations (E516L, D578V, and E648L) at the primary Ca(2+) site completely remove Ca(2+) regulation, placing the exchanger into a constitutively active state. These are the first data defining the role of CBD2 as a regulatory domain in the Na(+)-Ca(2+) exchanger.
About this Structure
2QVK is a Single protein structure of sequence from Canis lupus familiaris. Full crystallographic information is available from OCA.
Reference
The second Ca2+-binding domain of the Na+ Ca2+ exchanger is essential for regulation: crystal structures and mutational analysis., Besserer GM, Ottolia M, Nicoll DA, Chaptal V, Cascio D, Philipson KD, Abramson J, Proc Natl Acad Sci U S A. 2007 Nov 20;104(47):18467-72. Epub 2007 Oct 25. PMID:17962412
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