2FWS

First Ca2+ binding domain of the Na,Ca-exchanger (NCX1)

2FWS の概要

• エントリーDOI: 10.2210/pdb2fws/pdb
• 関連するPDBエントリー: 2fwu
• NMR情報: BMRB: 7009
• 分子名称: Sodium/calcium exchanger 1, CALCIUM ION (2 entities in total)
• 機能のキーワード: beta-sandwich, greek key, cis-proline, beta-bulge, ca2+ binding, metal transport regulator
• 由来する生物種: Canis lupus familiaris (dog)
• 細胞内の位置: Cell membrane; Multi-pass membrane protein: P23685
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 15243.67

構造登録者

Hilge, M.,Aelen, J.,Vuister, G.W. (登録日: 2006-02-03, 公開日: 2006-04-18, 最終更新日: 2024-05-29)

主引用文献

Hilge, M.,Aelen, J.,Vuister, G.W.
Ca(2+) regulation in the na(+)/ca(2+) exchanger involves two markedly different ca(2+) sensors
Mol.Cell, 22:15-25, 2006

PubMed Abstract: The plasma membrane Na+/Ca2+ exchanger (NCX) is almost certainly the major Ca2+ extrusion mechanism in cardiac myocytes. Binding of Na+ and Ca2+ ions to its large cytosolic loop regulates ion transport of the exchanger. We determined the solution structures of two Ca2+ binding domains (CBD1 and CBD2) that, together with an alpha-catenin-like domain (CLD), form the regulatory exchanger loop. CBD1 and CBD2 are very similar in the Ca2+ bound state and describe the Calx-beta motif. Strikingly, in the absence of Ca2+, the upper half of CBD1 unfolds while CBD2 maintains its structural integrity. Together with a 7-fold higher affinity for Ca2+, this suggests that CBD1 is the primary Ca2+ sensor. Specific point mutations in either domain largely allow the interchange of their functionality and uncover the mechanism underlying Ca2+ sensing in NCX.

PubMed: 16600866
DOI: 10.1016/j.molcel.2006.03.008

実験手法

SOLUTION NMR