3V5U

Structure of Sodium/Calcium Exchanger from Methanocaldococcus jannaschii DSM 2661

Summary for 3V5U

• Entry DOI: 10.2210/pdb3v5u/pdb
• Related: 3V5S
• Descriptor: Uncharacterized membrane protein MJ0091, SODIUM ION, CALCIUM ION, ... (8 entities in total)
• Functional Keywords: lipid cubic phase, cation protein complex, sodium, calcium exchanger, membrane protein, alpha helical, superfamily of cation, cation binding, membrane, metal transport
• Biological source: Methanocaldococcus jannaschii
• Cellular location: Cell membrane; Multi-pass membrane protein (Probable): Q57556
• Total number of polymer chains: 1
• Total formula weight: 38558.59

Authors

Jiang, Y.,Liao, J.,Li, H.,Zeng, W.,Sauer, D.,Belmares, R. (deposition date: 2011-12-16, release date: 2012-02-22, Last modification date: 2024-02-28)

Primary citation

Liao, J.,Li, H.,Zeng, W.,Sauer, D.B.,Belmares, R.,Jiang, Y.
Structural insight into the ion-exchange mechanism of the sodium/calcium exchanger.
Science, 335:686-690, 2012

PubMed Abstract: Sodium/calcium (Na(+)/Ca(2+)) exchangers (NCX) are membrane transporters that play an essential role in maintaining the homeostasis of cytosolic Ca(2+) for cell signaling. We demonstrated the Na(+)/Ca(2+)-exchange function of an NCX from Methanococcus jannaschii (NCX_Mj) and report its 1.9 angstrom crystal structure in an outward-facing conformation. Containing 10 transmembrane helices, the two halves of NCX_Mj share a similar structure with opposite orientation. Four ion-binding sites cluster at the center of the protein: one specific for Ca(2+) and three that likely bind Na(+). Two passageways allow for Na(+) and Ca(2+) access to the central ion-binding sites from the extracellular side. Based on the symmetry of NCX_Mj and its ability to catalyze bidirectional ion-exchange reactions, we propose a structure model for the inward-facing NCX_Mj.

PubMed: 22323814
DOI: 10.1126/science.1215759

Experimental method

X-RAY DIFFRACTION (1.9 Å)