4.5 Article

Proton paths in the sarcoplasmic reticulum Ca2+-ATPase

期刊

BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
卷 1767, 期 11, 页码 1310-1318

出版社

ELSEVIER SCIENCE BV
DOI: 10.1016/j.bbabio.2007.07.010

关键词

SERCA1a; Ca2+ pump; Na,K-ATPase; proton countertransport; proton pathway

向作者/读者索取更多资源

The sarcoplasmic reticulum Ca2+-ATPase (SERCA1a) pumps Ca2+ and countertransport protons. Proton pathways in the Ca2+ bound and Ca2+-free states are suggested based on an analysis of crystal structures to which water molecules were added. The pathways are indicated by chains of water molecules that interact favorably with the protein. In the Ca2+ bound state Ca(2)E1, one of the proposed Ca2+ entry paths is suggested to operate additionally or alternatively as proton pathway. In analogs of the ADP-insensitive phosphoenzyme E2P and in the Ca2+-free state E2, the proton path leads between transmembrane helices M5 to M8 from the lumenal side of the protein to the Ca2+ binding residues Glu-771, Asp-800 and Glu-908. The proton path is different from suggested Ca2+ dissociation pathways. We suggest that separate proton and Ca2+ pathways enable rapid (partial) neutralization of the empty cation binding sites. For this reason, transient protonation of empty cation binding sites and separate pathways for different ions are advantageous for P-type ATPases in general. (c) 2007 Elsevier B.V. All rights reserved.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.5
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据