Structure of cation channels, revealed by single particle electron microscopy

FEBS Letters

Sokolova, Olga¹ 

[1] Howard Hughes Medical Institute, Department of Biochemistry, Brandeis University, 415 South Street, Waltham, MA 02454-9110, USA

关键词: Cation channel;    Electron microscopy;    Labeling;    EM;    electron microscopy;    IP3R;    inositol trisphosphate receptor;    RyR;    ryanodine receptor;    CMC;    critical micelle concentration;    GFP;    green fluorescent protein;   

DOI  :  10.1016/S0014-5793(04)00254-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A large barrier in the way to obtaining high-resolution structures of eukaryotic ion channels remains the expression and purification of sufficient amounts of channel protein to carry out crystallization trials. In the absence of crystals, the main available source of structural information has been electron microscopy (EM), which is well suited to the visualization of isolated macromolecular complexes and their conformational changes. The recently published EM structures outline native conformations of eukaryotic cation channels that until now have eluded crystallization. According to these results, homo-tetrameric K⁺ channels have a distinct two-layer architecture with connectors conjoining the two layers, while the pseudo-tetrameric Ca²⁺ or Na⁺ channels are more globular and have flexible surface loops, which makes the identification of subunits complicated. Subunits can be identified using atomic structure docking into the EM maps, labeling, or deletion studies.

【 授权许可】

Unknown